With no explanation, chose the best option from "A", "B", "C" or "D". States, upon the filing of an appropriate pleading, may declare the rights and other legal relations of any interested party seeking such declaration, whether or not further relief is or could be sought. Any such declaration shall have the force and effect of a final judgment or decree and shall be reviewable as such. 28 U.S.C. § 2201. A district court’s decision to exercise its discretion and issue a declaratory judgment “will not be overturned absent a showing of clear abuse of ... discretion.” Kunkel v. Cont’l Cas. Co., 866 F.2d 1269, 1273 (10th Cir.1989). Bayouth and Hastings urge us to “assume that the District Court decided that [they] were not necessary parties,” Aplt. Br. at 11, and to then follow Federal Kemper Insurance Co. v. Rauscher, 807 F.2d 345, 353-54 (3d Cir.1986) (<HOLDING>), Harris v. Quinones, 507 F.2d 533, 536-37

A: holding that the insurers declaratory relief action presented a justiciable controversy for the injured parties even though the insured tortfeasor had suffered a default judgment
B: holding that the injured party had standing to appeal the declaratory judgment in favor of the insurance company and noting that it was decisive to the holding that dairyland named the injured appellants in its declaratory judgment action
C: holding that the district court erred in dismissing the injured party from the insureds declaratory relief action based on a default judgment entered against the insured and the insureds tortfeasor son
D: holding that where all necessary parties  including the insurer the insured and the third party claimant  had stipulated to the material facts in the dispute a declaratory judgment action on the insurers duty to indemnify could proceed
A.