I'm not a hundred percent sure, but you can eliminate a and b right away. What do THOSE have to do with global trade? Option C explains the Islamic community of Arabia, where the Bedouins traveled with their camels in caravans to trade with cities like Baghdad, Mecca, and Medina. So my little explanation there should help you find your answer! Just don't want to give you an answer because I'm not sure that my answer is the right one. Good Luck!
