Which of the Following Is True About the Caliphate in the Early

Which of the following is true about the caliphate in the early eighth century?

A) The caliphate exceeded the power of the Roman emperors.
B) The caliphate was in decline compared to its ascendant power in the seventh century.
C) The caliphate was the most powerful governmental entity among similar institutions in the Mediterranean world.
D) The caliphate was repressing the pursuit of knowledge and artist interests.
E) The caliphate served as a model that western emperors used to reform their own governments.