President Dwight D. Eisenhower was the first president to explain the domino theory, although he never actually called it the domino theory. He was explaining it in regards communism in Southeast Asia.
Correct answer is: C. The lowest-level vassal in a feudal system.
Under Feudalism, there was a peasant status called Serfdom. Serfs were bound and tied to the land, if sold they came with it. It was not slavery itself, but under the feudalism they were definitely the lowest form of "tenant" of the land.
