Answer :
Final answer:
Canada's most prominent contribution to the Allied air effort in World War II was its pilot training program, part of the British Commonwealth Air Training Plan. The correct option is (3).
Explanation:
In World War II, Canada notably contributed more to the Allied air effort than any other Commonwealth country through its renowned pilot training program.
This initiative was part of the British Commonwealth Air Training Plan (BCATP), which saw Canada become the primary location for training Allied pilots, navigators, bomb aimers, wireless operators, air gunners, and flight engineers.
Although Canada also participated in other areas such as aircraft production and women's contributions on the home front, it was the extensive pilot training program that stood out most prominently in their contribution to the Allied forces' air capabilities during the conflict.