Concept:The Kanem-Borno Empire grew wealthy by dominating a key trade route and commodity.
Explanation:The empire sat on important trans-Saharan trade routes.
This position gave it control over the exchange of valuable goods.
Among these goods, salt was the most vital and profitable commodity.
Because salt was in high demand and scarce in many regions, its trade brought great wealth.
By taxing and regulating this trade, Kanem-Borno rulers strengthened their economy and political power.
Answer:The correct option is the salt trade.