How has the foreign policy changed from 1945

 In the years after World War II, the United States was guided generally by containment — the policy of keeping communism from spreading beyond the countries already under its influence. The policy applied to a world divided by the Cold War, a struggle between the United States and the Soviet Union.

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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: