What were the principal reasons for the revolutions that broke out in europe in the decades after the congress of vienna?

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:

it was displayed because they had a love for war

which statement best describes the relationship between the fourteenth amendment and the african american civil rights movement?