The Romans viewed C) martyrs as a threat to the empire.
Martyrs, often individuals who died for their faith (especially Christians), were seen as a challenge to the Roman authority, which expected subjects to show loyalty through participation in the state religion and emperor worship. Martyrdom illustrated the strength of faith and commitment, often inspiring others to resist Roman rule.
However, it's important to note that both Christians (A) and Jews (B) were also considered threats at different times due to their religious practices and beliefs that resisted Roman norms.
Patriarchs (D) as a term generally refers to leaders in certain religious traditions, so they wouldn't be categorized in the same way as the other options in the context of this question.