The Nez Perce Indians of Idaho Were Goaded into War

The Nez Perce Indians of Idaho were goaded into war when

A) the Sioux began to migrate onto their land.
B) gold was discovered on their reservation.
C) the federal government attempted to force them onto a reservation.
D) the Canadian government attempted to force their return to the United States.
E) the U.S. government reneged on a treaty agreement to permit the Nez Perce to keep their native lands.