Answer :
"D. During the reign of Askia Muhammad, the Songhai empire reached its greatest size" would be the best answer from the list, but there were other factors.
The correct answers are:
A. Songhai leader Sunni Ali conquered Mali and destroyed the city of Timbuktu.
D. During the reign of Askia Muhammad, the Songhai empire reached its greatest size.
Songhai Empire was an empire that was ruled by the leading ethnic group and elite the Songhai. They were Muslims who had once been conquered by the Mali Empire, but later the Mali Empire weakened and the Songhai rebelled. Because of this, the Songhai formed an empire and conquered Timbuktu and other Mali lands. Askia Mohammad was known as the Askia the Great, he strengthened the empire and made it the largest empire in West Africa’s history.