Hi there! Just by looking at the answer choices and telling you what they mean, the answer is definitely not A, because it's cold in the Arctic, or D, because it's too mountainous to do the best farming there. The Canadian Cordillera is another mountain range, which again, it's too mountainous to farm there. The plains are the best place to farm, because the land is flat, and you have resources so that you can farm easily. The answer is C: Interior Plains.