To what degree was the supreme court responsible for undoing the constitutional gains of reconstruction

Beginning in 1873, a series of Supreme Court decisions limited the scope of Reconstruction-era laws and federal support for the so-called Reconstruction Amendments, particularly the 14th and 15th, which gave African Americans the status of citizenship and the protection of the Constitution, including the all-important right to vote. Bill, passed by Radical Republicans in Congress in 1867, that treated Southern states as divided territories. Sometimes called the Military Reconstruction Act or the Reconstruction Act, the First Reconstruction Act divided the South into five districts, each governed by martial law. It was the first of a series of harsher bills that the Radicals passed that year.

i believe the answer is c