Which of the Following Statements Best Described the Legal Status

Which of the following statements best described the legal status of Native Americans before they became U.S.citizens?

A) They became legal residents through the Fourteenth Amendment.
B) They were considered members of tribal nations whose relations with the United States were based on treaties.
C) They were considered enemy combatants by the U.S. government.
D) They were considered white, non-citizens, since 1776, but they have suffered de facto discrimination.
E) They were illegal residents.