The doctrine of containment set forth by George F. Kennan called for which of the following?

A) The United States seeking to "roll back" communism in Eastern Europe
B) The United States building a metaphoric wall of policies to isolate communist countries from the rest of world, including keep them out of the UN
C) The United States initiating arms reduction talks
D) The United States blocking the spread of communism to additional countries
E) No trade between capitalist countries like the United States and communist countries like the Soviet Union