The correct answer to this open question is the following.
Although there are no options included, we can say the following.
Soviet Supreme leader Joseph Stalin scared Eastern European citizens into complying during the spread of communism in that the Soviet leader sent Soviet troops to these countries and maintained the military presence and threat during the following years after World War II.
Stalin wanted to create a buffer zone in case the Western European countries tried to invade the Soviet Union. That is how Stalin spread Communism in countries such as Poland, East Germany, Hungria, Rumani, Albania, and Czechoslovakia.