With no explanation, chose the best option from "A", "B", "C" or "D". S.Ct. 1967, 124 L.Ed.2d 1 (1993) (in addressing motion for declaratory judgment district court has discretion in determining whether to exercise jurisdiction even when established). It is appropriate for a district court to address only the infringement issue when non-infringement is clear and invalidity and un-enforceability are not plainly evident. Id. (citing Leesona Corp. v. United States, 208 Ct.Cl. 871, 530 F.2d 896, 906 n. 9 (1976)). My discretionary power to dismiss GM’s and OnStar’s invalidity and unen-forceability counterclaims as issues that no longer need to be addressed is separate from determining whether I retain subject matter jurisdiction over such counterclaims, which remains a murky issue. Compare Fort James Corp. v. Solo Cup Co., 412 F.3d 1340, 1348 (Fed.Cir.2005) (<HOLDING>) with Benitec Australia, Ltd. v. Nucleonics,

A: holding that district court erred in determining that jury verdict of noninfringement divested district court of jurisdiction to hear unenforceability counterclaim
B: holding that district court correctly determined that it had been divested of jurisdiction to hear defendants counterclaims for invalidity and unenforceability when plaintiff had voluntarily dismissed its infringement claims without prejudice before trial
C: holding district court erred in setting aside jury verdict and entering judgment as a matter of law
D: holding that notice of appeal of district court opinion denying arbitration stay divested district court of jurisdiction to continue proceedings until the appeal was complete
A.