The Byzantine Empire Began

The Byzantine Empire began

A) in the 9th century C.E., with the missionary work of Cyril and Methodius.
B) in the 4th century C.E., with the establishment of Constantinople as the eastern capital of the empire.
C) in the 1st century C.E., during the reign of Augustus.
D) in the 5th century C.E., with the fall of Rome.