The correct answer is D) a state rule is overruled by federal law when the two conflict.
The supremacy clause ensures that a state rule is overruled by federal law when the two conflict.
The Supremacy clause can be found in Article VI of the United States Constitution. The basic idea is that it declares that federal laws have jurisdictional authority over the state laws when there is a cond¿flcit between the two. So when two parts have a conflict regarding state legislation and federal legislation, the US Constitution assures that federal law is always going to rule over the state law.
The other options of the question were A) a federal law is overruled by state law when the two conflict. B) the Supreme Court can always intervene in conflicts between private citizens. C) state and federal laws apply to totally separated subjects.
