The best explanation of the relative significance of the trans-Saharan and Indian Ocean trade routes is:
C. The Indian Ocean basin was more significant because it connected the Middle East and parts of Africa with Asia, specifically China, and it had imported goods such as silk and porcelain.
While the trans-Saharan route was indeed important for its trade in valuable resources like gold and salt, the Indian Ocean trade network had a broader reach and facilitated more extensive cultural and economic exchanges, linking a variety of regions including Africa, the Middle East, and Asia. This network was crucial for the exchange of a wide range of goods, including luxury items like silk and porcelain, fostering significant interactions among diverse cultures.