What does the red line represent on the map below?

Territory gained by

USSR in 1945

Countries under

communist control

Yugoslavia

Finland

communist but

Independent

USSR

East

Poland

Gemany

West

Germany

Czechoslovaka

Austria Hungary

Romania

Italy

Yugoslavie

Bulgaria

Turkey

AThe 38th Parallel

B Border between WWII Allied and Axis nations

The Iron Curtain

DThe breakup of Yugoslavia