Which of the following is a correct statement of federal preemption of state law under the Supremacy Clause? Choose 2 answers. Federal erwironmentallows will always preempt a state's water pollution law for its state parks. A state law that requires documentation of citizenship is preempted by the National Voter Registration Act because the act only requires a statement under oath. Federal law only preempts state law when Congress has expressly stated the preemption for the entire field DA state's attempt to regulate television and radio is preempted by federal law because the federal government has regulated the entire field