Answer:
b. To prevent Eastern Germans from leaving.
Step-by-step explanation:
The Communist governmental structure regime was falling apart in the waning days of the Cold War, and to ensure that Eastern Germans were unable to run away into sections of West Germany, the USSR & Eastern German government erected the Berlin Wall. This cut off all communications of West Berlin to the Western half of Germany as well, which initiated the Berlin Airlift. Following the Berlin Airlift, the USSR lifted the wall, and soon fell into disarray after.