The growth of Ghana, Mali, and Songhai was based on a. their exportation of cotton, indigo, and sugar
b. their control of the Trans-Atlantic slave trade
c. their conversion to Islam
d. their control of trade routes in Saharan Africa

d

Explanation:

i think ...i dont know much but i hooe u get ur ans

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).