Final answer:
Sir George-Étienne Cartier was the key figure who led Quebec into Confederation, contributing significantly to the formation of the Dominion of Canada.
Step-by-step explanation:
The individual who led Quebec into Confederation was Sir George-Étienne Cartier. Confederation in Canada was a process in which the British North American colonies united to create the Dominion of Canada.
This crucial event was part of the broader set of negotiations and decisions that formed Canada as a nation. Sir George-Étienne Cartier, a key political figure from Quebec, played a significant role alongside figures such as Sir John A. Macdonald, who became the country's first Prime Minister.
Cartier's contribution was essential in assuring that Quebec would enter into this new federal union, thereby providing the province a sense of security and representation within the greater structure of the Dominion of Canada. Therefore, the answer to the question is B. Sir George-Étienne Cartier.