On 12th March 1947 Truman made a speech to Congress announcing what would later be known as the Truman Doctrine. Truman referred to every nation as to choose between two ways of life and declared it was the policy of the United States to 'support free people who are resisting attempted subjugation by armed minorities or by outside pressures'. This gave any country that demonstrated it was in danger of Communist threat the support and backing of the US. The policy he outlined aimed to 'contain' Communism and not to diminish it. So the answer is C
