Most of canada's population lives a. in its cities b. in the mountains c. on its northern border d. on its southern border

The correct answer is - D. on its southern border.

The biggest portion of the Canadian population is concentrated in its southern part, along the southern border, which is the border with the United States. There's two big reasons for this phenomena:

- Climate;

Canada is a country where the climate is not very suitable for living in most of its territory as it is mostly sub-arctic and arctic climate. On its southern part, the climate is more pleasant, where there's change of seasons, pleasant summers, and also much bigger influence from the sea, and that brings in more precipitation, and also makes the climate more mild.

- Economy;

The cities, towns, villages, being so close to the border of the United States, and the large economic centers of this country, gives the people bigger opportunities from economic aspect. Since they travel without any restrictions across the border, they can work in the United States, can trade with its companies with ease, and can communicate on a daily basis.