Answer:
D. The president airlifted supplies to keep the Soviet Union from taking Berlin.
Step-by-step explanation:
I think the answer is D. According to a source, "The U.S. government was shocked by the provocative Soviet move, and some in President Harry S. Truman's administration called for a direct military response. Truman, however, did not want to cause World War III. Instead, he ordered a massive airlift of supplies into West Berlin."