What accounts for the spikes in american defense spending in the 1950's?
entry into un
afghan war
vietnam war
korean war

"Korean War"

Explanation:

The Korean War took place between 1950 and 1953. Its components were the Republic of Korea (or South Korea), supported by the armed forces of several countries commanded by the United States; and the Democratic People's Republic of Korea (or North Korea), supported by the People's Republic of China and the Soviet Union. The war was one of the earliest episodes of the Cold War. Excluding more than 3 million civilians and almost 15% of the population of the dead North, it constitutes one of the most bloodthirsty wars in history.

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:

i believe it was spain