Final answer:
The three conferences that led up to the BNA were the Tehran Conference, the Washington Naval Conference, and the Berlin Conference.
Step-by-step explanation:
The three conferences that led up to the BNA (British North America) were:
- The Tehran Conference, which took place in 1943 and involved the "Big Three" leaders - Churchill, Roosevelt, and Stalin. This conference addressed various issues related to World War II and the postwar settlement.
- The Washington Naval Conference, held in 1921, aimed to limit the naval arms race among major powers, including Britain, the United States, and Japan.
- The Berlin Conference, organized by Otto Von Bismarck in 1884, divided up Africa among European powers, establishing spheres of influence and conquest.