The Trail of Tears in 1838-1839 and the Battle of Wounded Knee in 1890 are significant because they

ADemonstrate the technological superiority of United States troops over the indigenous peoples of North America
BTypify the harsh treatment of native peoples at the hands of the U.S. government
CExemplify the determination of the American government to bring unity to North America and undermine any attempts at secession
DAdded large portions of land to the U.S. which had been controlled by foreign powers