Answer:
A. U.S leaders worried that Vietnam could spread communism throughout the region.
Explanation:
Eisenhower's "domino theory," the possibility that on the off chance that one nation in Southeast Asia tumbled to the communists, the whole locale would fall, and the gradually expanding influences would be felt all through the Asia-Pacific world, educated not just his reasoning about U.S. relations with the area however the policy making of his successors, John F. Kennedy and Lyndon B. Johnson.
Kennedy affirmed that Americans would “pay any price, bear any burden” to help law based country working as an approach to counter socialist advances in Asia. Amid Johnson's administration, the U.S. heightened its war in Vietnam, beginning with the Gulf of Tonkin Resolution in which Congress approved Johnson to utilize military power without proclaiming war. In March 1965, U.S. Marines arrived at Danang.
