The correct answer is C. 3
Step-by-step explanation:
The U.S. territory is divided into different geographical regions depending on geographical features such as relief. In the case of the Great Plains, this is a region located at the center of the U.S. territory and that goes from the North the South of this country including states such as Nebraska, Colorado, the Dakotas, Texas, Oklahoma, among others. Moreover, this region is known as the Great Plains because it includes mainly flat territory.
In the map, the region is shown by number 3 because this region which is at the center of the territory, extends from north to south and includes the states previously mentioned. Also, on the map, it is shown this territory does not include high mountains.