With no explanation, chose the best option from "A", "B", "C" or "D". rule. Id. at 538-40, 78 S.Ct. at 901-02. The Court first explained that the state rule was not “an integral part of the special relationship created by the [workers’ compensation] statute”, but was “merely a form and mode of enforcing the immunity ... and not a rule intended to be bound up with the definition of the rights and obligations of the parties”. Id. at 536, 78 S.Ct. at 900. In addition, the federal policy of having juries decide disputed questions of fact was an “essential characteristic” of the federal system, strongly influenced by the Seventh Amendment. Id. at 537-38, 78 S.Ct. at 900-01. For the Court, the importance of this federal policy outweighed the state rule. The Supreme Court’s subsequent decision in Hanna v. Plumer, 380 U.S. 460, 85 S.Ct. 1136, 14 L.Ed.2d 8 (1965) (<HOLDING>), does not prevent us from applying Byrd to the

A: holding that state substantive rules of decision apply in federal diversity cases
B: holding that federal court sitting in diversity should apply fed r crv p 4 rather than conflicting state rule because federal rule was consistent with rules enabling act
C: holding that a federal district court sitting in diversity must apply its forum states choice of law rules
D: holding that federal courts sitting in diversity shall apply state substantive law
B.