The correct answer is B) Vietnam War.
Letter A is incorrect because the Korean War happened during the early 1950's when Eisenhower was president so this cannot be right.
Letter C is incorrect because the Civil rights movement was already happening in places like Alabama, Arkansas, etc.
Letter D is incorrect because the passage has nothing to do with the expansion/abuse of power by the executive branch. Rather, this passage warns about the development of the US as a military industrial complex.