In a well-written paragraph, evaluate continuities and changes in cultural and economic interactions between societies in both West Africa and the Americas by answering these questions: How did the development of gold and salt mining impact the culture and economy of Ghana and Mali?

The gold-salt trade in Africa made Ghana a powerful empire because they controlled the trade routes and taxed traders. Control of gold-salt trade routes helped Ghana, Mali, and Songhai to become large and powerful West African kingdoms. ... Trade routes were most responsible for aiding the early spread of Islam. Ghana's rulers gained incredible wealth from trade, taxes on traders and on the people of Ghana, and their own personal stores of gold. They used their wealth to build an army and an empire. Extensive trade routes brought the people of Ghana into contact with people of many different cultures and beliefs."In addition, with these trade goods came the Islamic religion, ideas in art and architecture, and cultural practices. Whoever controlled the salt trade also controlled the gold trade, & both were the principal economic pillars of various West African empires.

The answer should be b.