What led to the Plains Wars during the nineteenth century?%0D%0A%0D%0A%0D%0AA. %0D%0Athe killing of Sitting Bull to deter the Ghost Dance movement%0D%0A%0D%0A%0D%0AB. %0D%0Athe death of General Custer at the Battle of Little Bighorn%0D%0A%0D%0A%0D%0AC. %0D%0Athe encroachment of white settlers on American Indian land%0D%0A%0D%0A%0D%0AD. %0D%0Athe forced assimilation of American Indians under the Dawes Act

C. the encroachment of white settlers on American Indian land