Does anyone understand this??

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:

keeping a cash reserve because cash flow is the the movement of money through a company and if it just sits there, it wont the movement

yes.

explanation:

because it let the japanese know who had the upper hand in the war.

d and a is the correct anwsers

explanation: