How can a court invalidate a state statute?

A court can invalidate a state statute primarily by declaring it unconstitutional. This occurs when a court determines that the statute violates provisions of the U.S. Constitution or the state constitution, thus making the law unenforceable. This judicial review power ensures that all laws are consistent with constitutional guarantees and fundamental rights.

In addition to declaring a statute unconstitutional, a court may also invalidate a state statute by determining that it is preempted. Preemption occurs when federal law takes precedence over state law in areas where the federal government has the authority to legislate, thus rendering state statutes that conflict with federal law void.

Both actions of declaring a law unconstitutional and recognizing preemption can effectively invalidate state statutes, making this option the most comprehensive choice. The correct answer reflects a full understanding of how courts can exercise their power to uphold constitutional integrity and federal authority.