What principle defines the apportionment of power between state and national governments?

The correct answer highlights the foundational concept of federalism embedded in the U.S. Constitution. It is derived primarily from the Tenth Amendment, which states that powers not delegated to the federal government nor prohibited to the states are reserved to the states or the people. This principle ensures that any authority not explicitly given to the national government remains with the states, allowing for a division of power that supports both state sovereignty and national unity.

This understanding of apportionment reflects a balance where both state and federal governments operate within their designated areas of authority. The states retain significant power to legislate on a variety of issues, such as education, transportation, and local law enforcement, while acknowledging national supremacy in matters specifically enumerated in the Constitution.

The other options do not capture the essence of this principle. The notion that all legislative power belongs to Congress suggests a lack of power for state governments, which is contrary to the federal structure. The idea that states have no authority over federal laws is overly simplistic and ignores the nuanced relationship wherein states can implement laws as long as they do not conflict with federal statutes. Finally, the assertion that federal law always supersedes state law does not reflect the importance of state powers defined in the Constitution, although it's true that federal law takes