The Plains Indians Were Finally Forced to Surrender and End

The Plains Indians were finally forced to surrender and end their resistance to losing their lands

A) because they were decimated by their constant intertribal warfare.
B) when they realized that agriculture was more profitable than hunting.
C) after such famous leaders as Geronimo and Sitting Bull were killed.
D) when the government extended a better offer to relocate the Plains Indians to unoccupied, large Western lands.
E) by the coming of the railroads and the virtual extermination of the buffalo.