Which of the Following Best Describes the Truman Doctrine

Which of the following best describes the Truman Doctrine?

A) An American doctrine discouraging the Western European powers from further interference in the Middle East
B) An American doctrine designed to prevent Soviet expansion
C) An American doctrine pledging the support of the United States to Israel in the eventuality of threats to its sovereignty
D) An American doctrine pressuring American allies to assume greater responsibility for their own military defenses