The United States thought that if Communism could not be contained, then countries would fall to Communism like dominoes were the policy of containment and the domino theory related.
Communism refers to separation of citizens in to separate groups having different ideas and in sense there is a construction of communities. The spread of community during the cold war.
As a result, a containment policy was implemented to prevent the development of communism in the United States of America.
Thus, option D is correct.
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