The correct option is D Muslim traders
Before the discovery of the sea route to India, the Silk Road was the
most important connection between the East and West. It experienced its
last great era during the time of the Mongol Empire. This ancient trade
route starts in the old capitals of Luoyang and Xian (then called
Chang'an), reaches the Yellow River at Lanzhou, then skirts westward
along deserts and mountains before dividing into three routes at the
oasis of Dunhuang.