The correct answer is "Accusations of bribery against the Grant Administration."
This can be the only correct answer, as the first, second, and fourth statements are incorrect.
Even though Grant (a Republican) won the election of 1868, he actually helped with Reconstruction. Grant sent in federal troops to help protect the rights of African-Americans in the Southern states. This shows that the first two statements are incorrect.
The fourth statement cannot be correct, as it was the Democratic party who lead attacks against the voting rights of African-Americans during Reconstruction.
This shows that only the second one can be correct.
