Religiously,how Were the Early Abbasid Leaders Different from the Roman

Religiously,how were the early Abbasid leaders different from the Roman and Tang leaders?

A) The first Abbasid rulers could claim direct descent from prophet Muhammad.
B) The Roman leaders were never Christian until the fall of the empire.
C) Roman and Tang leaders never withdrew their support from their subjects' religion.
D) Roman and Tang leaders were not generally seen as both secular and religious leaders.
E) The Roman and Tang leaders were not associated with being founders of the religion of their people.