The correct answer is C) establishment of the Freedmen's Bureau.
The acts by Congress that were intended to prevent this repressive social and political order were the establishment of the Freedmen's Bureau.
In a time of ecom¿nomic problems and political instability, the Freedmen's Bureau was a real help for former black slaves and poor white people that lived in the south and practically had nothing after the conclusion of the American Civil War.
The US Congress approved the establishment of the Freedmen's Bureau in 1865 to assist these people with medical attention, food, shelter, and education. Unfortunately, there was not enough money to accomplish these, besides the political "climate" in the racist's southern states never accepted this Freedmen's Bureau.