Under the 10th Amendment, who retains powers not delegated to the federal government?

The correct answer is that states and the people retain powers not delegated to the federal government as articulated in the 10th Amendment. The 10th Amendment explicitly states that the powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people. This means that any authority that is not specifically granted to the federal government by the Constitution is automatically reserved for states or the people, reinforcing the principle of federalism in which both the national and state governments have specific domains of authority.

In the context of the other options, the President, the Supreme Court, and Congress pertain to branches of the federal government that have specifically designated powers. The President carries out federal laws, the Supreme Court interprets those laws, and Congress makes the laws. Since the 10th Amendment serves to limit federal reach and empower states and individuals with the rights not explicitly granted to the federal level, the role of the federal branches does not align with the premise of reserving certain powers as indicated in the 10th Amendment. This foundational element of the Constitution effectively maintains the balance between state and federal authority, ensuring that local governance can respond to the needs of its citizens.