Some of President Richard Nixon's most important achievements were in foreign policy. Which of the following did he accomplish?
A. He was the first American president to visit China, which opened the door to future possibilities.
B. He established peace and understanding with Fidel Castro in Cuba.
C. He guided America to victory in Vietnam and the soldiers were welcomed home with an enormous celebration.
D. He negotiated the reunification of North and South Korea, which created new trade opportunities for the United States