The correct answer is - Agriculture.
The Great Plains region in the United States, is a vast region that is almost exclusively an agricultural land where multiple types of food and fiber products are produced, but also manufactured. Most of the agricultural land of the Great Plains is planted with wheat, corn, barley, canola, soy beans, cotton, and sorghum, and the United States are one of the biggest exporters on the global markets of this products. The economy of the Great Plains region is almost entirely dependent on the agriculture.
