Which American Indian group lived in the Great Plains region?

In the mid-1700s, Plains tribes started riding horses that had been brought over from Europe. Groups such as the Blackfeet, Sioux (pronounced SOO), and Comanche (pronounced kuh-MAN-chee) became master riders and warriors, and they controlled huge hunting grounds that supported thousands of members.

Explanation:

In the mid-1700s, Plains tribes started riding horses that had been brought over from Europe. Groups such as the Blackfeet, Sioux (pronounced SOO), and Comanche (pronounced kuh-MAN-chee) became master riders and warriors, and they controlled huge hunting grounds that supported thousands of members.

Explanation:

b is the answer i am assuming