The best answer to describe how the Silk Road changed over time is:
A. The silk road changed to reflect changing political borders and power structures.
The Silk Road was not a single, unchanging route but rather a network of trade paths that evolved due to various factors, including the rise and fall of empires, shifts in political boundaries, and changes in trade demand. As new powers emerged (like the Mongol Empire, which facilitated trade in the 13th and 14th centuries) and others declined, the routes took on different characteristics, with new cities emerging as key trade hubs while others became less significant. Additionally, geopolitical developments, such as wars and the establishment of new trade agreements, influenced how and where trade was conducted along these routes.