Answer:
C the federal government and Native Americans.
Step-by-step explanation:
America's westward expansion following the Civil War did indeed result in conflict between various groups, particularly between white settlers and Native American tribes.
As the United States government encouraged and facilitated the settlement of the western frontier through the Homestead Act and other policies, white settlers began to encroach on Native American lands, often without regard for the treaties that had been made with those tribes. This led to many conflicts and battles, such as the Battle of Little Bighorn in 1876, where the U.S. Army, led by General George Custer, was defeated by a coalition of Native American tribes.
Additionally, tensions arose between different groups of white settlers as they competed for resources, such as land and water. The range wars between cattle ranchers and sheepherders in the late 1800s and early 1900s are an example of this kind of conflict.