Which of the Following Best Defines Federal Preemption

Which of the following best defines federal preemption?

A) It is a constitutional doctrine that empowers the Congress to regulate commerce with foreign nations, with Indian tribes, and among the states.
B) It is a constitutional doctrine declaring that any federal law or treaty that directly conflicts with a state or local law is void.
C) It is a constitutional doctrine whereby the legislative branch enacts laws, the executive branch sees that the laws are executed, and the judicial branch interprets the laws.
D) It is a constitutional doctrine stating that in an area in which federal regulation is pervasive, state legislation cannot stand.