Answer :
The correct answer is (3) - Soviet Union. The part of the World under the influence of Soviet Union was said to be behind the "iron curtain" and had socialism as the economic system.
The Soviet Union exerted political and economic control over Poland, Hungary, and Romania immediately after World War II. Option 3 is coorrect.
The Soviet Union, officially named the Union of Soviet Socialist Republics (USSR), was a socialist state in Eurasia that lasted from 1922 to 1991.
It extended over 10,000 kilometres (6,200 mi) east to west across 11 time zones, and over 7,200 kilometres (4,500 mi) north to south.
The Soviet Union originated in the 1917 October Revolution.