The correct answer is D) the Ku Klux Klan.
The group that was formed during Reconstruction and used violence and terror to try to prevent freed slaves from voting and enjoying other civil liberties was the Ku Klux Klan.
The white supremacist group called the Kuklux Klan (KKK) was founded in Pulaski, Tennesse in 1865 and had most of its presence in the Southern states of the US during 1870 as opposition and violent group against the Reconstruction program established by the government. It was a group of people that offended and intimidated physically African Americans. Nathan Bedford Forrest was the first leader of the clan. So it is true that the KKK was formed during Reconstruction and used violence and terror to try to prevent freed slaves from voting and enjoying other civil liberties.