Answer:
c. policy makers believed that if we did not fight, it would embolden the communists
Explanation:
The wars in Korea and Vietnam were both part of the Cold War between the United States and the Soviet Union. Both in Korea and Vietnam there were strong and ever growing movements that were communist and they had their affinity toward the Soviets. The United States did not wanted to allow that this two important strategic countries fall under control of the communists, so they decided to get involved and fought wars on both places. The end result was mixed, as Korea was divided on two parts, one of which remained communist, while in Vietnam, the American army was humiliated and lost, so the communists took over all of the country.