In What Way Did Truman Establish the Foundation of U

In what way did Truman establish the foundation of U.S.policy for the next forty years?

A) He adopted the "domino theory" in regard to the spread of communism, stressing the need for an aggressive strategy to limit it to Eastern Europe.
B) He sought to spread communism by supporting armed minorities who were attempting to subjugate Eastern Europeans.
C) He emphasized the need to use isolationism instead of interventionism when responding to the growth of communism.
D) He continued and expanded Roosevelt's efforts to collaborate with Stalin and the Soviet government rather than feeding into tensions.
E) He believed the United States only needed to address communism within Russia, not in other countries around the world.