The correct answer is:
A. Salt mines in the Sahara desert
Explanation:
The Songhai Empire (14th and 15th century) controlled the area of the Niger River to the Atlantic Coasts, with the city of Gao as its capital. The Songhai Empire was one of the largest of its time and was governed by the Sonni dynasty. Trade was one of the main activities that transformed the Songhai Empire into a commercial center, they controlled the production and trade of salt from salt mines in the Sahara desert; other goods the Songhai Empire traded were cloth, arms, copper and horses.
