Answer:
A. The Tet Offensive
Step-by-step explanation:
The Tet Offensive made U.S. leaders realize that there was no end in sight for the Vietnam War. Therefore, the answer is A. The Tet Offensive.
The Tet Offensive was a major military campaign launched by the North Vietnamese and Viet Cong forces against South Vietnam and the United States in January 1968. Although the offensive was eventually repelled by U.S. and South Vietnamese forces, it was a significant turning point in the Vietnam War. The Tet Offensive demonstrated that the North Vietnamese and Viet Cong were still capable of launching large-scale attacks and that the U.S. military's strategy of attrition was not working.
The Tet Offensive led to a shift in public opinion in the United States against the war, as many Americans had believed that the U.S. was making progress in the conflict. The offensive also led U.S. leaders to realize that there was no end in sight for the Vietnam War and that a new strategy was needed to end the conflict.