To what extent were the civil rights of African Americans protected after the Civil War?

To what extent were the civil rights of African Americans protected after the Civil War?
a. Attempts to protect the civil rights of African Americans after the Civil War were largely unsuccessful for decades.
b. No attempts were made to protect the civil rights of African Americans until Reconstruction ended.
c. The civil rights of southern African Americans were considerably greater than their northern counterparts.
d. It was two decades after the Civil War before African Americans had civil rights that were comparable to those of whites.