Concept:Islam spread peacefully through commercial and social interactions with Muslim traders along West African trade routes.
Explanation:The spread of Islam in West Africa was not mainly driven by force or conquest.
It was aided by the trans-Saharan trade network linking North Africa with West Africa.
Muslim merchants crossed the desert regularly to exchange goods such as gold, salt, and cloth.
Through these repeated business contacts, they built trust, friendship, and mutual respect with local communities.
Markets and trading towns became centers where Islamic ideas, teachings, and culture were shared and discussed.
Because the traders dealt with people honestly and peacefully, their faith became attractive to the locals.
Effective trade relationships thus opened the way for many West African rulers and their subjects to accept Islam willingly.
Answer:C. effective trade relationship.