How Did "Redeemer" Conservative Democrats Come to Power in the South

How did "redeemer" Conservative Democrats come to power in the South during the 1870s?

A) by forming a close coalition with northern Democrats
B) by adopting a pro-Republican position that favored Reconstruction policies
C) by using the race issue to excite the white electorate and threaten black voters
D) through fair and free elections ensured by federal troops
E) with the support of the black vote after redeemers promised to protect black suffrage