Which of the following statements best describes islam's spread from the seventh through the 17th century?
a. military conquests by the arab empire and traders of islamic faith were the primary means for spreading islam to africa, europe, and asia.
b. islam reached north, sub-saharan, and east africa, but did not take hold in asia.
c. the arab empire rejected military conquest; therefore, trade and missionaries were the primary means for spreading islam beyond the arabian peninsula.
d. the spread of islam was limited to the areas of the arabian peninsula where muhammad traveled.