One of the Main Reasons That the Sioux Were Able

Multiple Choice

One of the main reasons that the Sioux were able to develop control over a substantial area in North America was that

A) many other tribes, such as the Cheyenne and Crow, joined them.
B) they received assistance from the British government.
C) they built cities and developed a superior network of trade.
D) smallpox epidemics helped in their conquests.