The Roman Empire fell around the fifth century, and as Islam spread in the seventh century, trade between Europe and China slowed. Chinese traders were blocked from westward expansion into Europe when the Chinese army was defeated by Muslim fighters in the area known as Syr Darya. The trade routes, known as the Silk Road, fell into disuse, and trade between the Far East and Europe nearly stopped. It wasn't until the thirteenth century when the Mongols invaded and controlled central Asia and large parts of the Middle East that extensive trade along these routes was opened again.

Which statement is true about the Mongol empire?
A.
The Mongols unified regions along the Silk Road, allowing for safe transport of goods.
B.
The Mongols replaced the Roman Empire as the dominant force in Western Europe.
C.
Without access to European markets, the Chinese were unable to obtain raw materials.
D.
Muslims controlled busy trade routes into China from the fifth to the seventh centuries.

A. The Mongols unified regions along the Silk Road, allowing for safe transport of goods.