Final answer:
Vancouver is the city in Canada that requires the highest share of household income to cover ownership costs, making it less affordable than Toronto, Montreal, and Ottawa.
Step-by-step explanation:
The city in Canada that requires the highest share of household income to cover ownership costs is Vancouver. Historically, Vancouver has been known for its high real estate prices, which translates into significant ownership costs relative to household income. Various housing affordability studies and surveys, such as the ones conducted by RBC Economics and the Canadian Real Estate Association, have often pointed to Vancouver as the city with the least affordable housing market when compared against other major Canadian cities like Montreal, Toronto, Ottawa, and others. Thus, the correct answer to the question is c. Vancouver.