The answer is B. USSR
The Cold War was a state of tension after World War II between the United States of America and their NATO allies and the countries that the Eastern Bloc consisted of - The Soviet Union and the allies from the Warsaw Pact.
I is called cold because no actual fighting was involved, but there were many proxy wars, supported by the two sides. The two countries were observed as superpowers with two generally different systems. The USSR was a former Marxist-Leninist state, dominated by a single party, planned economy and controlled press, and US stood as a relatively free democratic country. The Cold War lasted from 1947 to 1991.
