What effect did the slave trade have on africa?

The slave trade on Africa has caused lots of wars. The slave traders did not  go and kidnap their own slaves, but instead, they bought it from the coastal kingdoms. So to keep having slaves to sell, they used to rage wars on some tribes to kidnap slaves and sell them. The coastal kingdoms even waged sometimes wars on each other if they try to get slaves from the same tribe, or any other reason. This ruined the economy and culture of Africa. The slave trade is one of the reasons Africa is such an undeveloped country today, because all the Africans that could maybe help development has been captured and slaved.

Aor b but i'm going with b