A plaintiff brought a negligence action in federal court to recover damages for injuries suffered as an audience member at an event held by the defendant. The defendant was a citizen of the forum state; the plaintiff was a citizen of the neighboring state in which the event was held. Under the forum state's choice-of-law rules, the negligence law of the neighboring state applied to this action. Under the negligence law of the neighboring state, the defendant owed a duty to the plaintiff. Under the negligence law of the forum state, the defendant did not owe a duty to the plaintiff. Which law should the court apply in deciding this action?
a. The negligence law of the forum state, because that is the law of the state in which the federal court sits.
b. The negligence law of the forum state, because choice-of-law rules are procedural rules.
c. The negligence law of the neighboring state, because of the forum state's choice-of-law rules.
d. The negligence law of the neighboring state, because the plaintiff is a citizen of this state.