What Is the Claim to Fame of Hiram Revels and Blanche

What is the claim to fame of Hiram Revels and Blanche K.Bruce?

A) They were the only black men to serve as state governors in the nineteenth century.
B) They were the only black men to serve in the U.S.Senate until the second half of the twentieth century.
C) They were the first black men to serve in a presidential cabinet,under Grant and Hayes respectively.
D) They cast the deciding votes which resulted in President Johnson's impeachment.