State governments must follow which type of laws.

The answer is: US federal law

Even though the state governments has the right to create their own law, The US federal law had a supremacy over the law created by the state governments.

This mean that if the laws that created by the state and the federal government contradict each other, the state government must obey/follow the law created by the federal government.

the answer is d.index

answer; sociological imagination;