The correct answer is C) Byzantine Empire.
Diocletian split the Roman Empire into two halves to be ruled by co-emperors. Later, when Rome collapsed in the West, the name of the empire that held on in the East was the Byzantine Empire.
The Byzantine empire is the Eastern Roman Empire. It's capital city was Constantinople, founded by Constantine. The Eastern portion of the Roman Empire controlled territories in the Balkans, Greece, Italy, North Africa, and Asia Minor. Constantine changed the official language of the Byzantine Empire, from Latin to Greek.
