For option C:

1. Roman clergy = Cardinal bishops following the papal election law in regard to constitutive norms. These are a subset of the College of Cardinals anyway. So if the entire college was doubtful but the Roman clergy were not doubtful, then that smaller group could make sense as a competent subject. But an ecuмenical council would be more secure.

2. Universal Church = Ecuмenical Council with approval of last living Pope. This is the Council of Constance solution. This solution already worked. This would be the preferred solution because it would include the maximum number of validly-ordained bishops and would therefore calm consciences.

• Roman clergy as historically prior electors: In the classical manuals, “Roman clergy” refers to the presbyters and deacons of the Roman Church—the original electing body before the later development of the College of Cardinals.
• Cardinal bishops as later juridical development: Cardinal bishops are not simply a subset of the Roman clergy; they are a later, papally‑constituted organ.
• Fallback logic in total collapse: If the College became doubtful or unusable, the manuals argue that the Church could revert to the historically prior subject—not because they are a subset of the College, but because they are the root from which the College historically developed.

• Constance as a providential, not normative, model: Constance worked because Gregory XII was alive and could authorize it.
• Natural‑law fallback does not require papal approval: In the hypothetical scenario contemplated by Cajetan, Suárez, and John of St. Thomas, there is no certain pope—and therefore no one who can authorize a council.
• Universal Church acting in extremis: The manuals teach that in a true collapse, the universal Church (represented by an imperfect council) could act precisely because no pope exists to authorize anything.

• Sacramental vs juridical: episcopal consecration (ontological) is distinct from jurisdiction (juridical); remedial supply can address juridical defects without denying sacramental reality.
• Objective triggers: devolution is triggered primarily by physical impossibility (death, capture, total communications blockade); manifest heresy becomes a trigger only when it produces universal, insurmountable doubt about elector identity.
• Publicity and evidence: every extraordinary act must rest on public facts, multi‑regional corroboration, notarized records, and a waiting period to prevent partisan claims.

• Backstop model: treat Cassiciacuм as a metaphysical continuity claim—if a credible materially‑present claimant exists, the council formalizes or recognizes his authority.
• Recognition/formalization model: the council’s public act is decisive; Cassiciacuм language may be used interpretively but is not required as the legal basis.
• Elective/repair model: if no credible material claimant exists, the council proceeds to elect under strict safeguards, creating both material and formal status by public canonical act.
• Hybrid model: prefer a conditional approach—recognize and formalize a credible material claimant when demonstrable; otherwise elect under the Governing Principle.

• Convocation: convene by surviving public ecclesial authorities or a multi‑regional committee when ordinary convocation is impossible.
• Eligibility: admit only validly consecrated bishops with public attestations; residential jurisdiction is preferred but not absolute if corroboration exists.
• Evidence and timing: require attestations from at least three distinct regions, docuмentary proof, notarized minutes, oath‑taking, and a canonical waiting period (recommended 30 days).
• Publication and provisionality: publish all acts and state explicitly that decisions are provisional and subject to later canonical regularization.

• First step — correction: prioritize public correction and rehabilitation; summon the person, offer a clear opportunity for recantation, and docuмent any reconciliation.
• Second step — juridical declaration: if heresy is public, notorious, and obstinate, treat the person as having lost any legitimate claim ipso facto once the high evidentiary bar is met, and proceed to formalize another candidate or elect.
• Third step — provisional action: if neither correction nor clean juridical declaration is possible, treat the claimant as functionally impeded and act provisionally to restore governance while preserving a path for later review.

This should be put here as well for those interested: https://ttu-files.s3.us-east-2.amazonaws.com/The_Election_of_the_Pope.pdf

Within he states:

Bishops without jurisdiction cannot elect the Pope

We have seen that in abnormal circuмstances the election of the Pope - according to the thought of the theologians who have dealt with the question - falls to the imperfect General Council, in other words to the Bishops and prelates who enjoy, in the Church itself, jurisdiction. The Pope is, in fact, Bishop of the universal Church: it is therefore normal that exceptionally it is the prelates of the universal Church governing, like him and below him, a portion of the flock who elect him. We have also seen that by the very nature of things, and as a consequence of what has been said, are excluded from the number of electors per accidens of the Pope, titular Bishops, Bishops consecrated with the Roman mandate but deprived of jurisdiction in the Church. A fortiori are excluded from the number of electors - precisely because they are excluded from the General Council - Bishops consecrated without a Roman mandate under the exceptional conditions of the current (formal) vacancy of the Apostolic See. These Bishops were indeed consecrated validly and even, in our opinion - at least in certain cases - lawfully; but nevertheless they are - in the most absolute way - deprived of jurisdiction by the fact that the Bishop receives jurisdiction from God only through the intermediary of the Pope, an intermediary excluded in our case (14). Being deprived of jurisdiction, they do not belong to the hierarchy of the Church according to jurisdiction, for which they are not ex officio members of the Council and are therefore not entitled to validly elect the Pope, not even in cases extraordinary. This point of doctrine, already established in itself, is confirmed by the practical impossibility of electing a reliable and undoubted Pope by following this path. Who will be able to establish with certainty, among the many Bishops who have been and will still be consecrated in this way, those who have the right to participate in the election and those who do not? Who has the right to convene the Conclave and who does not? Who can be considered as legitimately consecrated and who not? In the absence of criteria of discernment (the Roman mandate, the residential seat) there are no limits per se to these consecrations neither on the part of who can authorize them (the Pope) nor with regard to the portion of territory to be governed (the diocese). The number of voters can therefore grow disproportionately without any guarantee of their catholicity, as has happened in practice.

- - END QUOTE - -

And in another place it was claimed,

"The anonymous author accepts Pivarunas’ proof that the Holy See is vacant but shows that “universal Church” in Cajetan means an imperfect general council of bishops holding ordinary jurisdiction. Because strict (total) sedevacantism concedes no such bishops today, only the Cassiciacuм (material-formal) thesis can preserve apostolic succession and a future election."
https://www.truecatholicfaith.com/articles/p/2asy6yaysnrh7dbgvxe9zp7iyq25wy


And here is the formed response based on the exercise so far:

Rebuttal: Bishops without Jurisdiction and Devolution in Extremis

• Thesis and summary. 
  In a true catastrophic collapse of the Church’s ordinary juridical organs, the classical manualist tradition permits a remedial corporate response: validly consecrated bishops who lack ordinary jurisdiction are not ipso facto excluded from participating in an emergency assembly or election when the Church supplies the necessary juridical capacity under strict, public safeguards. This position preserves apostolic succession and visible continuity without adopting metaphysical alternatives (e.g., Cassiciacuм) as the only solution.
• Sacramental character distinct from juridical power. 
  The ontological fact of episcopal consecration is distinct from the grant of jurisdiction. St. Thomas and the manualist tradition teach that orders confer an indelible character even when juridical faculties are absent; therefore a bishop’s sacramental capacity remains a real basis for corporate action when positive juridical structures fail.
• The remedial principle in the scholastic tradition. 
  Cajetan’s and Suarez’s formulations of devolution express a remedial principle: when the competent judge is impeded, the Church acts by those who can (paraphrase of Cajetan) and, if ordinary electors fail, the power devolves to the universal Church or the Roman clergy (Suarez, paraphrase). Read together, these teachings authorize the Church to supply juridical competence corporately in extremis rather than to leave apostolic primacy without remedy.
• Imperfect council as a form, not a fixed juridical body. 
  The imperfect council is a remedial form the Church may assume; it is not identical to a canonical ecuмenical council composed only of bishops who already possess ordinary jurisdiction. John of St. Thomas and other manualists envisage the Church acting through those who remain publicly able to act, which can include sacramentally valid bishops whose jurisdictional defects are temporarily supplied by the Church’s corporate will.
• Why jurisdictional exclusion cannot be absolute. 
  To insist that no bishop without a Roman mandate may ever participate would create a logical dead end in scenarios where no ordinary electors survive or can be used. Classical theologians avoid that dead end by allowing natural‑law supply: positive law governs ordinarily, but natural law and the Church’s corporate life provide extraordinary remedies to preserve visible succession.
• Distinguishing physical impossibility from moral defect. 
  The proper, objective trigger for devolution is physical impossibility—death, capture, permanent disappearance, or total communications blockade. Moral defects such as manifest heresy are a different category; they can produce practical impossibility only when they have objectively and universally destroyed the Church’s ability to identify and rely on electors.
• When widespread manifest heresy becomes a practical trigger. 
  Manifest heresy qualifies as a devolution trigger only when all of the following obtain simultaneously: (a) Universality — the heresy is publicly notorious across the entire electoral subject; (b) Indeterminacy — no elector can be credibly certified as orthodox or trustworthy; (c) Incapacity to adjudicate — no independent tribunal can judge the fact without circularity; and (d) Irreversibility for the foreseeable future — communications or canonical processes cannot restore reliable identification within a reasonable canonical interval. Only such a compound factual state converts moral defect into practical impossibility.
• Evidentiary standards and Bellarmine’s caution. 
  The manualist insistence on public notoriety is decisive here: Bellarmine’s technical teaching that a manifest heretic loses office ipso facto presupposes public notoriety, not private accusation. Therefore any claim that heresy has produced practical impossibility must be certified by public facts meeting a high evidentiary bar.
• Who convokes and who may convene. 
  When ordinary convocation is impossible, surviving public ecclesial authorities—senior metropolitans, the most public bishops remaining, or a multi‑regional committee—may lawfully convene an imperfect council. This follows the scholastic pattern that the Church acts through those who remain able to act publicly for the good of the whole.
• Eligibility to vote: sacramental validity plus public attestation. 
  Eligibility should be limited to bishops who are validly consecrated and whose consecration can be publicly attested. Residential jurisdiction is prudentially preferred but not an absolute ontological disqualification if corroboration exists. Public certification, docuмentary proof, and regional representation are the operative criteria.
• Procedural safeguards to prevent proliferation and factionalism. 
  To answer the critic’s practical worries, impose strict safeguards: (a) multi‑regional corroboration (recommendation: attestations from at least three distinct ecclesial regions); (b) docuмentary proof of consecration and public acts; (c) public notarization and contemporaneous minutes; (d) oaths of fidelity by conveners and electors; and (e) a canonical waiting period (e.g., 30 days) for contestation. Suarez’s prudential cautions and Billot’s insistence on public proof justify these measures.
• Avoiding circularity in adjudication. 
  Determinations that remove or exclude electors cannot be self‑authenticating. Claims of manifest heresy or jurisdictional illegitimacy must be adjudicated by a public corporate act under the evidentiary rules above, not by unilateral partisan declarations. This preserves the distinction between public facts and private accusations.
• Why Cassiciacuм is not the only viable route. 
  The Cassiciacuм (material‑formal) thesis is a metaphysical solution that preserves a material pope deprived of formal authority; it is one possible response but not the only theologically defensible route. The classical devolution doctrine supplies a corporate juridical remedy that preserves succession without adopting Cassiciacuм’s metaphysical distinctions.
• Practical model (concise procedural summary). 
  The operative sequence in extremis should be: (1) certify impossibility publicly with multi‑regional attestations; (2) convene representative bishops under oath; (3) admit only sacramentally valid bishops with public proof; (4) deliberate and, if necessary, elect following ancient Roman‑clergy principles adapted to the circuмstances; (5) record and publish minutes with civil or ecclesial notarization; (6) seek later canonical regularization if ordinary organs reappear.
• Conclusion and theological balance. 
  The classical authorities—Cajetan, Suarez, John of St. Thomas, Bellarmine, Billot, and Journet—converge on a balanced solution: the Church’s visibility and apostolic succession are indefectible, but the historical mode of juridical visibility is not. In true extremis the Church may act corporately to supply what positive law cannot, provided that the remedial action is constrained by high evidentiary standards, public procedures, and prudential safeguards designed to preserve catholicity and prevent opportunism. This preserves both doctrinal integrity and practical continuity without making metaphysical constructs the only available remedy.

• maintain that only bishops with legitimate jurisdiction can participate

They talk about that in the interview.