Radical Congressional Reconstruction of the South Finally Ended When

Radical congressional Reconstruction of the South finally ended when

A) the South accepted the Thirteenth, Fourteenth, and Fifteenth Amendments.
B) the last federal troops were removed in 1877 and a "solid" Democratic South became politically institutionalized.
C) President Johnson was not reelected in 1868.
D) the Supreme Court ruled in Ex parte Milligan that military tribunals could not try civilians.
E) blacks showed they could defend their civil rights adequately in state courts and legislatures without federal congressional and military intervention.