The correct answer is D) is a series of rivers and mountains that separates Canada from the US.
The continental divide is a series of rivers and mountains that separates Canada from the US.
A continental divide is the area or the territory that physically divides the rivers' systems of a continent. Let's have in mind that the rivers feed into the sea. For instance, we have the Great Divide in North America that ends in South America. It starts in Alaska, passes through the Rocky Mountains, then through the Sierra Madre Occidental mountain chain in Mexico, and ends in the Andes Mountains of Peru.