The Soviets established the Warsaw Pact to
A) crush independence movements in Hungary and Poland.
B) solidfy their control over Easter Europe.
C) solidfy their control over Southeast Asia.
D) help Poland remain independent.
The best answer to this (of the ones you suggest) is B. The Soviets created the Warsaw Pact to make their control over Eastern Europe more secure.
The Warsaw Pact was created to be a counterbalance to the United States and its NATO alliance. The Soviets created the pact in part to try to ensure that the Western nations would not be able to overrun them.
However, a major purpose of the Warsaw Pact was to pull the countries of Eastern Europe closer to the Soviet Union. As the salem-history link below says,
The period following Stalin’s death in 1953 had seen considerable diversity and agitation for increased independence on the part of the Eastern European satellite states...
It was in response to these actions that the Soviets created the Warsaw Pact.
The answer is B. In response to the formation of NATO (North Atlantic Treaty Organisation) by the West, the Soviet Union established the Warsaw Pact, which allowed the superpower to formalise their military ties with their satellite states in Eastern Europe so as to maximise their potential as buffer states against the West.