One of the central factors in the establishment of trans-Saharan trade was the A. Invention of lighter, but still powerful, artillery. B. Use of large caravans of donkeys. C. Spread of a common religion. D. Invention of a wider horseshoe. E. Increased use of the camel

E. Increased use of the camel

Explanation:

The central factors in the establishment of trans-Saharan trade was the increased use of the camel.

The camels replaced the use of caravans as a means of movement of goods and people from one place to another. It was a more durable way of movement because the camels were stronger and they could survive very harsh and more tedious conditions.