What major airline operates hubs at Vancouver International Airport?

Air Canada is the major airline that operates hubs at Vancouver International Airport (YVR). It serves as one of the key bases for Air Canada's operations, facilitating both domestic and international flights. With a significant presence at YVR, Air Canada connects travelers to numerous destinations across Canada, the United States, and international locations, showcasing the airport's role as a vital gateway for air travel in the region.

The choice of Air Canada as the correct answer reflects its established infrastructure and flight frequency at YVR compared to the other airlines listed. While WestJet operates at Vancouver International and provides many flights, its primary hub is at Calgary International Airport. United Airlines and Delta Airlines also serve YVR, but their operations do not qualify as hubs, as they primarily function as connecting points rather than major operational bases. Thus, Air Canada's dominant position at YVR solidifies its role as the major airline in this context.