Which evidence from the text BEST supports the inference that President Truman initiated U.S. intervention policy that lasted beyond Greece and Turkey?

After World War II, the world has shifted from its fight to stop fascism to controlling the spread of communism. Many countries were torn after the events of the war, and communisms offered the suffering population of these nations a solution. The U.S. and many Western nations knew the core issues that communist countries had, and tried to stop the spread of it across Europe by helping to rebuild war-torn nations, all whilst spreading the benefits of free democracy.

On March 12th, 1947, President Harry Truman addressed Congress with his proposal to send $400 million in aid to Turkey and Greece after Britain announced they would be withdrawing from those nations. Greece and Turkey were essential in stopping communism, because if those countries fell, the communist wave would reach the Middle East and even Asia.

So, the Truman Doctrine laid out a plan (starting with Turkey and Greece) which led U.S. foreign policy throughout the Cold War. According to Truman, "It must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures". This Doctrine further led to justification for foreign action by the U.S. in Cuba, Korea, and Vietnam to fight the spread of communism.

Reference:

Truman Doctrine (1947) - National Archives

https://www.archives.gov/milestone-documents/truman-doctrine