What was one geographical feature that helped to isolate china?

Himalayan mountains

Explanation:

To the south and southeast of China are the Himalaya Mountains. These are the highest mountains in the world. They provided a nearly impassable border for Ancient China, keeping the area isolated from many other civilizations.

the answer is a. 250 percent.

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation: