Answer:
Correct answer is it served as a unifying force that helped launch an Arab empire.
Explanation:
First option is not correct as the conquest of Mongols came much later in the period of the Late Middle Ages.
Second option is correct because a Muslim Empire that stretched from Mesopotamia to Spain became a leading force in the region.
Third option is not correct as Persian Empire was already weakened by the Byzantines.
Last option is also not correct as the Byzantine Empire didn't had enough power to subdue new force that appeared in the nearby.
