Which of the following is one of the three territories in Canada?

Northwest Territories is one of the three territories in Canada, which also include Yukon and Nunavut. Territories in Canada are distinct from provinces in that they are governed differently and have a different relationship with the federal government. Territories have a more direct form of federal oversight and aren't granted the same degree of self-governance as provinces.

Quebec and Nova Scotia are provinces, characterized by their own governments and more autonomy than territories. British Columbia is also a province, located on the west coast of Canada. Each of these options, while significant in their own right, does not fit the specific classification of territory, making Northwest Territories the correct choice.