What was one main reason khrushchev was replaced as party leader?
a. his reforms created serious problems.
b. he was unable to win the space race.
c. his challenge to the us nearly caused a war.
d. he was forced to crush rebellions in other countries.

The correct option is A

Khrushchev was the leader of the Soviet Union during part of the Cold War. He served as first secretary of the Communist Party of the Soviet Union, between 1953 and 1964, and as president of the Council of Ministers, between 1956 and 1962. Khrushchev was responsible for the partial de-Stalinization of the Soviet Union, to support the progress of the program Soviet space and several relatively liberal reforms in matters of internal politics. His party colleagues removed him from power in 1964, replacing him Leonid Brezhnev as first secretary and Alekséi Kosygin as president of the Council of Ministers.

Some of Khrushchev's policies were seen as erratic, especially by his emerging rivals, who quietly rose strongly and deposed him in October 1964. However, he did not suffer the deadly fate of some earlier losers from the struggles over Soviet power being retired with an apartment in Moscow and a dacha in rural areas. His memoirs were smuggled to the West and partially published in 1970. Khrushchev died in 1971 of heart disease.

the answer is b. hope this !