The best explanation of the relative significance of the trans-Saharan and Indian Ocean trade routes is:
d. The routes were equally significant—each in its own way—as they both contributed to significant cultural developments along the routes, and worth cannot be measured simply by the goods that were traded.
Both trade routes had profound impacts on the cultures, economies, and social structures of the regions they connected. The trans-Saharan trade facilitated the exchange of goods like gold, salt, and slaves, while also fostering the spread of Islam and cultural exchanges in North and West Africa. The Indian Ocean trade network connected diverse regions, allowing for the exchange of valuable commodities like silk, porcelain, spices, and the sharing of ideas, technology, and cultural practices between Africa, the Middle East, and Asia. Thus, both routes were significant in their own rights, contributing to the development of complex societies and interactions across great distances.