What Is the Main Point of the Supremacy Clause

What is the main point of the supremacy clause?

A) It establishes that the Constitution and the laws of the United States are the law of the land and supreme to all laws passed by the state and local governments.
B) It establishes that the Articles of Confederation and the laws of the United States are the law of the land and supreme to all laws passed by the state and local governments.
C) It establishes that the laws of the state and local governments are the law of the land and supreme to all laws passed by the national governments.
D) It establishes that the national, state, and local governments have equal amounts of power.