Which amendment outlines that powers not delegated to the U.S. are reserved to the states?

The Tenth Amendment specifically addresses the allocation of powers not granted to the federal government by the Constitution, stating that such powers are reserved for the states or the people. This amendment reinforces the principle of federalism by ensuring that any authority not explicitly enumerated for the federal government is retained by the states. It ensures a balance of power, preventing the federal government from overstepping its bounds and encroaching on state sovereignty.

In contrast, the other amendments listed do not pertain to the distribution of powers between the federal government and the states. The Fifth Amendment involves rights related to legal proceedings and protection against self-incrimination; the Sixth Amendment focuses on the rights of criminal defendants, including the right to a fair trial; and the Ninth Amendment addresses the protection of rights not specifically enumerated in the Constitution. Each of these amendments serves a different purpose and does not concern the reservation of powers to the states.