Final answer:
The interior plains are located in the southern Prairie Provinces of Canada, specifically in Saskatchewan and Manitoba, making D. A & C the correct answer.
Step-by-step explanation:
The interior plains are geographical regions that feature extensive lowlands and are commonly associated with large-scale grain and beef farming. In Canada, the interior plains are primarily found in the southern Prairie Provinces. Specifically, they can be located in both Saskatchewan and Manitoba. Therefore, the correct answer to where the interior plains are found is D. A & C - Saskatchewan and Manitoba. These plains are recognized for their fertile farmland, which is well-suited to support large grain and beef operations, contributing significantly to the agricultural landscape of Canada.