Why is Northern Canada extremely cold?

Northern Canada is extremely cold primarily due to its location near the Arctic Circle. This area experiences long, harsh winters and short, cool summers due to its position at high latitudes. Because the sun's rays hit this region at a much shallower angle compared to more equatorial areas, there is less solar energy to warm the land. Additionally, the Arctic environment is characterized by ice and snow, which reflects sunlight rather than absorbing it, further contributing to the cold climate.

The other factors presented do not account for the extreme cold in the same way. High elevation can contribute to colder temperatures, but Northern Canada’s cold is not solely due to altitude. Proximity to the equator typically means warmer climates, which contrasts sharply with the frigid temperatures found in the north. Dense forests can have localized effects on climate but do not significantly influence the overall coldness of Northern Canada. Thus, the correct choice highlights the primary climatic influence from the region's geographic position.