NATO is the North Atlantic Treaty Organization also called The North Atlantic Alliance. It was created to ensures US military protection for the Europeans in case of aggression, but above all it gives the USA supremacy over the western bloc.
NATO was founded in 1949 in Washington but became less prominent after the end of the cold war.
D. is the correct answer. During the civil war medics where considered nuetral and were not shot. Sometimes medics would even help enemies lying on the battle field. Hope this helps!