A most extreme example of prejudice and racism in the United States in the 19th century was

A-immigration restrictions placed on Catholics and Irish immigrants
B-the abolition of slavery that occurred with passage of the Thirteenth Amendment
C-the removal of 16,000 Native Americans from their homes in the southeast to territories in the west.
D- racism against German-Americans and Italian-Americans due to the fact that these were enemy countries in World War I