The line that separated communist countries from free countries in europe was called “the iron curtain.”

The "Iron Curtain" was an imiginary line that separated the countries under the control of the communist Soviet Union from the Democratic countries of Western Europe. This phrase was first introduced by Winston Churchill in a commencment address. Ultimately, this imaginary line would lead to increased tensions throughout the middle of the 20th century. This was a line that was constantly referred to as countries like the United States and the members of the North Atlantic Treaty Organization tried to stop the spread of communism.

location is the answer to this

the answers is b.   environments.