Final answer:
Mainstream Protestant denominations do not share the characteristic of recognizing the Authority of the Pope, which is specific to Roman Catholicism.
Step-by-step explanation:
The characteristic that is not shared by mainstream Protestant denominations is B) Authority of the Pope. Mainstream Protestant denominations commonly share beliefs such as Belief in the Trinity, Emphasis on Scripture, and the Recognition of sacraments, but they do not recognize the authority of the Pope, which is a distinctive feature of Roman Catholicism.
Instead, Protestant churches typically hold to the principles of the priesthood of all believers and the autonomy of the local congregation.