The end of the trans-Atlantic slave trade resulted in

a decrease in money going to African kingdoms.

payment from the Americas to Africa.

Africa owing money to American slaveholders.

an increase of European goods in Africa.

a decrease in money going to African kingdoms

Explanation:

The end of the trans-Atlantic slave trade was a major economic blow for the African kingdoms. The African kingdoms made big portion of their profit from selling slaves that they have captured from the other tribes to the Europeans. Once the slavery was abolished, the money toward the African kingdoms stopped as well, which led to their weakening and eventually collapse, later being used by the Europeans to overtake them.