Select the african civilizations. mali assyria hindu congo aksum hittite aryan kush luba nubia lydia sumeria

c is the correct answer for this question.

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).