The correct answer is C) citizenship rights for freed slaves.
The option that was primarily a political challenge that the United States faced after the Civil War was " citizenship rights for freed slaves.
Civil War was officially ended, and the United States government had forbidden slavery in the US territory. United States President Abraham Lincoln tried to reintegrate the Confederated States to the Union during the Reconstruction period, but his anxiety to do it quickly allowed the Southern States leeway to do Reconstruction in their own terms. There were many issues such as the citizenship rights for freed slaves that needed to be resolved. Northern people had supported abolitionism before and during the Civil War. They were more open to integrate black people in society and grant them rights. But in the Southern States, the story was so different to the degree that they authorized the implementation of the black codes.