Plz help i will mark brainlies who ever has the correct anwser.

Which of the following was a key accomplishment of the people of songhai? a. they had a strong military and became the largest empire in west africa. b. they established a center of islamic scholarship. c. they worked with iron and prospered from the gold-salt trade. d. they dominated in the trade of ivory, enslaved people, and animal skins.

How did presidential reconstruction allow black codes to be passed

1. describe the concept of the unitary executive. discuss whether this concept is practical.