What reason did the Soviet Union give for its expansion after World War II?

Question

anonymous · Answer

The spread of communism and aggression were the main concerns of the western world. 

The Berlin air lift was on of those actions taken by the U.S. when the Soviets built a wall to isolate West Berlin. The formation of NATO was another result.

anonymous · Answer

A.	It allowed for more trading opportunities.
	B.	It created a buffer zone to protect it from invasion.
	C.	it had to deal with its rapidly grown population.
	D.	it want to give its people more opportunities to seek their fortunes.

surana · Answer

Four answers there are, not A, nor C, it sounds like D but is yet not the one you seek, what does the fourth answer minus two lead to?