Final answer:
Settlers sought to exterminate the buffalo population primarily to control the land and displace Native American tribes, as the buffalo were central to the tribes' sustenance and way of life. Therefore the correct answer is B) To control the land and displace Native American tribes
Step-by-step explanation:
Reasons for Buffalo Extermination During Westward Expansion
One of the primary reasons settlers sought to exterminate the buffalo population during westward expansion was To control the land and displace Native American tribes. The buffalo were integral to the lifestyles and cultures of the Native American tribes who lived on the Great Plains. Settlers and the U.S. government viewed the extermination of buffalo as a way to weaken the tribes' ability to resist relocation and to assimilate them into a farming lifestyle. The depletion of buffalo herds, facilitated by ranch hands and incentivized hunting, therefore served the settlers' interests in claiming land for farms, ranches, and railroad expansion, which represented a significant shift to a market economy in contrast to the nomadic lifestyle of the Native Americans.
The decimation of the buffalo was part of a broader strategy of forced assimilation and displacement that affected the Native American way of life drastically. This strategic extermination was underscored by various actions such as military confrontations, reservation systems, and legal policies aimed at curtailing tribal sovereignty and culture.