The "long march" of China was led by Mao Zedong so its C.
I think the answer is the 10th Amendment
The decline of the Roman Empire allowed for the nations of England and France to develop.
The Anglo-Saxons took over after the fall to form England. The rise of the Franks was where Germanic kings led loosely united clans which eventually formed into France.
A water route from The Netherlands to the china