The west african empires of ghana, mali, and
songhai were able to thrive because
(1) they controlled the gold-salt trade
(2) their herds of cattle were in demand
(3) their armies took control of much of africa
(4) they adopted christianity as their primary
religion

The West African empires of Ghana, Mali and Songhai were able to thrive because they controlled the gold-salt trade. The correct option among all the options given in the question is option "1". Ghana was one of the richest African nations during the time of the gold-salt trade. It not only controlled the gold-salt trade, but it also controlled all the trading routes that went through its land. It mainly controlled the trade routes between West and North Africa. The North African people wanted gold and the East African people wanted salt.

North eastern side i believe if that’s the answer you were looking for