Answer :
The correct answer is D) attacks from European Crusaders, Arabs, and Turks.
Attacks from European Crusaders, Arabs, and Turks were most responsible for the fall of the Byzantine Empire.
Constantine I, emperor of Rome, decided in 330 AD that Byzantium would be the capital of the Roman Empire.
After years of prosperity, the Byzantine Empire started to decline for its many debts and the many enemies and invasions it had to fight. The Battle of Manzikert in 1071, was the first of the major battles that started the final days of the empire. The Crusades, the worry of the constant Muslim threat to expand to the west, and internal conflicts that accelerated the ending of the Byzantine empire.