Final answer:
If a state law conflicts with a national law, the Supremacy Clause ensures that the national law is implemented, affirming the Constitution and federal laws as the supreme law of the land.
Step-by-step explanation:
When a state law conflicts with a national law, the Supremacy Clause of the Constitution declares that the Constitution, federal laws, and treaties are the supreme law of the land. This supremacy means that national laws prevail over state laws if they are within the national government's constitutional authority. This principle was solidified in the landmark Supreme Court case McCulloch v. Maryland in 1819, which affirmed congressional authority and prohibited states from taxing national institutions.
Hence, the correct answer to the question, 'What happens if a state law conflicts with a national law?' would be: A) The national law is implemented. The supremacy clause ensures that the legal hierarchy maintains federal laws and the Constitution above state laws. State and local governments retain the freedom to enact their legislation, but they must yield to federal statutes when a conflict arises, reflecting the constitutional intent to have one set of laws binding the nation together.