The correct answer to the question is:
4. Iron Curtain
Explanation:
1. The term "Iron Curtain" was used to describe the political, military, and cultural isolation enforced by the Soviet Union on its satellite nations in Eastern Europe after World War II.
2. This barrier symbolized the division between the communist Eastern Bloc countries under Soviet influence and the capitalist Western European countries.
3. The Iron Curtain physically and ideologically separated the Eastern and Western parts of Europe during the Cold War, restricting communication, travel, and interaction between the two sides.
4. This term was famously used by Winston Churchill in a speech in 1946 to illustrate the sharp divide and lack of freedom in the countries under Soviet control.
