Answer:
Blackfoot, Arapaho, Assiniboine, Cheyenne, Comanche, Crow, Gros Ventre, Kiowa, Lakota, Lipan, Plains Apache (or Kiowa Apache), Plains Cree, Plains Ojibwe, Sarsi, Nakoda (Stoney), and Tonkawa.
your answer is A.
Explanation:
1. primary source materials.
2. historiography
A) wartime conditions