Understanding Federalism and the Supremacy Clause

Federalism is a system of governance that divides powers between national and state governments. This division of authority can lead to conflicts, particularly regarding the scope of laws and the powers of each level of government. Consider a scenario in which a state government enacts a law that contradicts a federal law related to environmental regulations.

Which of the following principles best explains the constitutional framework that determines the outcome of such conflicts between state and federal law?