Question

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

Explanation:

Khrushchev's reforms, such as in agriculture and industry, had mixed results. Some of his hasty and ill - planned reforms led to inefficiencies and problems. For example, his agricultural policies like the Virgin Lands Campaign had environmental and productivity issues. While his actions in the space race (the Soviets had early successes like Sputnik) and the Cuban Missile Crisis (a challenge to the US) were significant events, the internal problems caused by his reforms were a major factor in his removal. Crushing rebellions (like in Hungary, although that was earlier) was more of a political action during his tenure but not the main reason for his removal compared to the reform - related problems.

Answer:

His reforms created serious problems.