The most important difference between the Truman Doctrine and the Eisenhower Doctrine demonstrated that
A
the United States wanted to increase economic aid to communist nations in Eastern Europe.B
the policies of the United States had been successful in halting the spread of communism.C
the United States later thought that military aid was needed in its fight against the spread of communism.D
it was no longer necessary for the United States to send economic aid to countries threatened by communism.