How did the Cold War between the United States and the Soviet Union begin?

A) the United States built a "Star Wars" defense system because the Soviet Union
invaded Afghanistan

B) Each superpower formed a European military alliance of the nations it had occupied
or protected during WW2.

C) The Soviet Union developed nuclear weapons that were superior to those of the
United States

D) The two superpowers went to war over Cuba in a conflict known as the Bay of Pigs