The correct answer is number 3.- They trained British pilots in effective air support techniques.
United States pilots contributed to the Allied war effort in Europe during World War II because they trained British pilots in effective air support techniques.
During World War II, air warfare was an important component of the battles between the Allied Forces and the Axis. That is why it was so important that United States pilots contributed to the Allied war effort in Europe during World War II training British pilots in effective air support techniques. The U.S. and England deployed air strategies for bombing raids on German cities. The Allied forces wanted to deploy air superiority to create a strategic advantage in the war.