Question

What was the United States' major concern about their former ally, the Soviet Union? A. that the Soviets would never leave Berlin B. that the Soviets would never leave Iran C. that the Soviets would join the United Nations D. that Soviet-style Communism would take over the world

Answer 1

maybe its answer is c

Answer 2

The answer is (D) that Soviet-style Communism would take over the world.

Although ally, USA was highly skeptical about the spread of communism is Asian countries.

At the time of World War II few countries in Asia continent were influenced by the communism, and the USA wanted to prevent this link to other countries.  

The scope and spread of communism was the major concern of  the USA against the USSR(contemporary).