What was the state religion? A) Imeria of Charlemagne, B) Byzantine Empire under Justinian,

What was the state religion? A) Imeria of Charlemagne, B) Byzantine Empire under Justinian, c) Arab Caliphate under Harun ar-Rashid

The empire of Charlemagne in the first half of the 9th century was a Christian state, and then the split of Christianity into Western and Eastern had not yet occurred. However, ante-Nicene Christianity already existed (ancient Eastern churches – Armenian, Coptic and others). Charles received the crown of the emperor in 800 AD from the hands of the Pope, at that time there were only two emperors in Europe – he was in Constantinople.
The Byzantine Empire in the 6th century was also a Christian state.
Harun-ar-Rashid was a contemporary of Charlemagne and the Arab Caliphate was Muslim under him.