The correct answer is B) Vietnamese civilians were being killed in US bombing raids.
One argument by those opposed to the War in Vietnam was that Vietnamese civilians were being killed in US bombing raids.
After the Tet offensive and the bad results for the US Army and South Vietnam, people in America became more concern about the United States participation in the War of Vietnam. People expressed many concerns and protesters took the streets to make their voice heard against the war. One of the arguments used by those opposed to the War in Vietnam was that Vietnamese civilians were being killed in US bombing raids.