Which of the Following Is a Reason That Communism Lost

Which of the following is a reason that communism lost its appeal in post-World War II western Europe?

A) Communist political parties were outlawed in western European countries.
B) Strong economic growth led to increased standards of living and expanded access to services like education and health care.
C) Observers who visited the Soviet Union were able to observe and report on the differences between communist theory and Soviet practice.
D) Europeans had successfully prosecuted Nazis and Fascists, so saw nothing to be gained from another authoritarian system such as communism.