Answer:
C. Cheyenne
Step-by-step explanation:
The Cheyenne tribe established their nation in the land that now belongs to the state of Montana. Due to the information contained in the question, we know that horses played a valuable role in the life of Deleep's tribe. This was true because of the vast distances the Cheyenne had to cover. We also know that buffalo inhabited the same area as Deleep's tribe. The geographic location of the Cheyenne nation corresponds well with the range of the bison.