What year did hitler launch operation barbarossa? ?

1941

Explanation:

In 1941 Adolf Hitler launched his troops in the Soviet Union to invasion. Around three million German Solider were sent to Soviet. But by the defeat of the German Solider in the Soviet Union was seen as a crucial turning point WW II because it showed the weakness of the German.  

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:

hilary clinton

explanation:

trump won the popular vote and ended up becoming the president in 2016 because of this and the electoral college.