Which of the following amendments prohibits cruel and unusual punishment?

The Eighth Amendment is the correct answer because it specifically prohibits the imposition of cruel and unusual punishments. This amendment emerged from the desire to restrict the government's authority in administering justice, ensuring that punishments are not only proportional to the crime committed but also humane. The language of the amendment reflects Enlightenment ideals, which emphasized the dignity of the individual and rejected barbaric practices in the penal system.

The 6th Amendment focuses on the rights of defendants in criminal prosecutions, including the right to a speedy trial and an impartial jury. The 10th Amendment deals with the powers not delegated to the federal government, thereby reserving those powers for the states or the people. The 12th Amendment establishes the process for electing the President and Vice President, ensuring that electors cast separate votes for each office. Each of these amendments serves a distinct purpose, but it is the Eighth Amendment that directly addresses the issue of cruel and unusual punishment.