Details you remember about the berlin wall, korean or vietnam war, cuban missile crisis, the arms race, the leaders, etc.

America, a capitalist country, wanted to contain communism to make sure that it would not take over the US. The Berlin Wall was a literal wall in separating east Berlin from West Berlin.
The Vietnam war and Korean was the north vs south conflict that involved two different forms of government wanting to rule.
The Cuban Missile Crisis happened during the Cold War(?) and threatened the United States. This happened when the Soviet Union(?) sent over missiles to communist Cuba.
The Cold War was US vs USSR and involved the threat of nuclear weaponry.

Is there not a question though?

The answer is c. good luck : )