Final answer:
The photo of the Great Mosque of Djenné exemplifies the historical process of the spread of Islam along trade routes in West Africa during the fourteenth century.
Step-by-step explanation:
The black and white photo of the Great Mosque of Djenné, Mali, illustrates the spread of Islam along trade routes. This historical process is well-documented, as Islam was established in Ancient Mali by the fourteenth century largely through interactions and trade with Berber traders who managed the trans-Saharan trade routes. The Great Mosque at Djenné first erected in the thirteenth and fourteenth centuries was a center of religious learning and scholarship and became a hub for Islamic academic pursuits in West Africa.
Islam in West Africa was generally spread by trade rather than by military conquest or colonization. Evidence suggests that the religion diffused throughout the region due to commercial exchange with Muslim traders and scholars who fostered the adoption of Islam by local elites and facilitated cultural diffusion. While some conversion may have occurred due to the tangible commercial incentives associated with adopting Islam, the religion also spread through schools, mosques, and social networks, contributing to a sense of unity and coherence among believers.