Part A
The statement that BEST summarizes the major impacts of the Mongolian invasions is:
The Silk Road trading routes between China and Europe increased positive economic relationships and cultural exchanges.
Part B
The statement that provides evidence for the answer to Part A is:
"By bringing the entire Eurasian landmass under a single rule, the Mongols increased trade, especially along the Silk Road. This new trade had a major impact on Europe."