President eisenhower believed in the domino theory, which states that a). if an aggressor nation invades one country successfully, it will invade another. b). if one country falls to communism, its neighbors are also likely to do so. c). if the united states can defeat one communist country, it can defeat them all. d). if one section of a country is taken over, the rest of the country will also fall.

B) If one country falls to communism, its neighbors are also likely to do so.

Explanation:

This fear of communism spreading was due to America's rivalry with the Soviet Union after World War II. This era of competition for global influence and power is known as the Cold War. During this time, the US worried about the spread of communism and the domino theory.

To prevent this domino theory from taking place, the US government adopted a policy of containment. Containment was focused on stopping the spread of communism to new countries. This is one of the reasons why the US would get involved in the Korean and Vietnam Wars.

d is the correct answer

~courtney