The correct answer is letter D
According to Truman's theory, the world was divided between two systems: the free democratic governments and the communist totalitarian. Foreign aid, as formulated in its 1947 doctrine, has been the White House's foreign and security policy guideline for several decades. Events that followed included the Marshall Plan for postwar European reconstruction, alliances such as the North Atlantic Treaty Organization (NATO), created in 1949, and interventions in Korea and Vietnam.