The US Constitution is referred to as the “supreme law of the land.” Option A is correct
The United States Constitution is The Supreme Law of the United States.
The Supremacy Clause in the Constitution states:
“This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding.”