Including the soviet union list two european countries in the communist bloc

The examples of such countries, could be: 
Poland, Romania, Czechoslovakia, Eastern Germany (German Democratic Republic). 
Those countries formally were independent states but their politics and economy was controlled by Moscow (the capital city of the Soviet Union). They were called the satellite countries. In term of economy all those countries were members of Comecon (Council for Mutual Economic Assistance) and in term of security - members of the Warsaw Pact. 

The border between the communist bloc and the western Europe was called "the iron curtain" - it was located between the Eastern and Western Germany. The communist bloc started falling apart  in 1989 along with the democratic revolutions taking place in the Eastern Europe.

Ithink the answer should be a.