Which amendment assigns responsibilities not specified in the Constitution to the states?

The Tenth Amendment to the United States Constitution is specifically designed to reserve powers not delegated to the federal government for the states or the people. This amendment is a critical component of the federalist structure of the U.S. government, emphasizing that any powers that are not explicitly granted to the national government by the Constitution should remain with the states or the citizens.

This provision was included to limit the power of the federal government and to ensure that states maintain a level of autonomy, allowing them to address local issues as they see fit. Therefore, when considering which amendment assigns responsibilities and powers not specified in the Constitution to the states, the Tenth Amendment stands out as the correct answer, reflecting the foundational principle of states' rights within the framework of American governance.

The other amendments listed do not focus on the delegation of powers to the states. The Fourteenth Amendment primarily addresses citizenship rights and equal protection under the law. The Sixteenth Amendment pertains to the federal government's right to impose income taxes. The Fifth Amendment deals with legal protections in criminal cases, such as the right against self-incrimination and guarantees of due process. Each of these serves distinct purposes that do not relate to assigning powers to the states, reinforcing why the Tenth Amendment is the correct choice