What Was the Significance of the Events in the Village

What was the significance of the events in the village of Mai Lai in 1968?

A) They represented how far American technology had advanced since the Second World War, as the American soldiers used several bombs against the Vietnamese troops.
B) The defeat of Vietnamese soldiers in a long-planned, complex attack boosted the morale of American soldiers, giving them the confidence they needed to quickly win the war.
C) U.S. soldiers suffered their greatest defeat of the Vietnam War because they had allowed themselves to trust Vietnamese soldiers disguised as civilians.
D) For the first time during the Vietnam War, American troops were stationed on the ground, and because it was so effective, the air war came to an abrupt end.
E) U.S. soldiers committed terrible atrocities against Vietnamese civilians, which ignited a public outcry and debate upon their exposure to Americans at home.