Question

Which scenario could occur without the supremacy clause?

Answer 1

The correct option is C.
The supremacy clause states that the under the constitution of the United States of America, the federal laws are superior to state laws, therefore in time of conflict between the federal and the state law, the state law has to bow to federal law. Thus, the supremacy clause is used when federal and state laws are in conflict. 

Answer 2

A state could ignore the 19th amendmant and pass a law forbidding women to vote (apex)