The correct option is "Plains"
These tribes occupy the central plains of the USA. and from southern and southeastern Canada (North Dakota, South Dakota, Nebraska, Kansas, Iowa, Montana, Oklahoma and part of Texas). The tribes of the area were dedicated to the hunt of the 'buffalo' and lived in a typical house called tipi, although those in the southern part (those of the Caddo language, Hidatsa and Mandan) had a developed agrarian culture. In this area inhabited most of the tribes of Sioux language (Hidatsa, Mandan, Sioux, Osage, Ioway, Omaha, Otoe, Missouria, Quapaw, Kanza), some Algonquian language (Blackfoot, Arapaho, Cheyenne, Atsina) and other of caddo language (wichita, pawnee, arikara) or na-dené languages (sarsi).