Question

How was Islam able to cross the Sahara desert in the 18th century?

A. At the time, the Sahara desert was smaller and less harsh than it is today
B. African slaves escaping from there Arab owners brought Islam home with them
C. A Muslim Army went south to conquer African kingdoms in Ghana and Sudan
D. Muslim merchants from north Africa followed trading routes through the Sahara desert

Answer 1

D. It seems like the most reasonable answer. And there were also trading routes established during those times.