Who discovered insulin, a hormone used to treat diabetes?

Discover Canada records this in one direct sentence. The guide writes: Sir Frederick Banting of Toronto and Charles Best discovered insulin, a hormone to treat diabetes that has saved 16 million lives worldwide. The two Canadians the test wants are therefore Sir Frederick Banting and Charles Best.

The discovery saved millions of lives. Discover Canada commits to a remarkable figure: insulin "has saved 16 million lives worldwide." So Banting and Best's discovery is one of the most impactful medical breakthroughs ever attributed to Canadian researchers — measured in millions of lives over many decades since.

The discovery happened in Toronto. Discover Canada identifies Banting as "of Toronto" — meaning Toronto is where the insulin discovery is most directly tied. Sir Frederick Banting was the senior figure (the title "Sir" indicates a knighthood), and Charles Best was his collaborator. Together the two Canadian researchers gave the world a treatment for a previously fatal condition.

Insulin is one of several Canadian medical and scientific contributions. Discover Canada lists many "Great Canadian Discoveries and Inventions," including: Alexander Graham Bell — who "hit on the idea" of the telephone; Joseph-Armand Bombardier — who invented the snowmobile; Sandford Fleming — who invented standard time zones; Reginald Fessenden — who contributed to early radio; and others. But for insulin, the discovery belongs specifically to Banting and Best — making them part of a long Canadian tradition of world-changing scientific discoveries.

The Toronto setting matters historically. Discover Canada's explicit identification of Banting as "of Toronto" places the insulin breakthrough in the largest Canadian city — already by the early 20th century an important medical-research centre. The discovery is one of the most cited Canadian medical contributions to world health, and Banting's later citizenship-test prominence reflects how central this discovery is to the Canadian self-understanding of scientific achievement.

The question is testing whether new citizens know who discovered insulin. Discover Canada commits to two Canadians: Sir Frederick Banting and Charles Best. The right test answer matches that.

The wrong answer choices each pick a different inventor. Alexander Graham Bell is also named in Discover Canada, but for the telephone idea, not insulin. Thomas Edison is not described in the guide as a Canadian researcher. The fourth option is also not a Canadian discoverer of insulin in the guide; Discover Canada credits Reginald Fessenden as a Canadian radio contributor, but for radio, not insulin. Only Banting and Best — Toronto researchers — discovered insulin.