A plaintiff who was a citizen of State A was traveling to adjoining State B to visit his relatives. While still in State A, the plaintiff's auto was struck in the rear by a vehicle driven by the defendant, a citizen of State B. The plaintiff suffered personal injuries and damage to his vehicle amounting to approximately $90,000. The plaintiff filed suit in the federal district court for State A and obtained proper service of process on the defendant. Under the laws of State A, the driver of a vehicle that strikes another vehicle in the rear is presumed to have acted negligently, regardless of the surrounding circumstances. Neither the law of State B nor the federal statutes or case law has adopted such a rule. Should the court apply the presumption in question