With no explanation, chose the best option from "A", "B", "C" or "D". However, Mr. Horler is seeking only the production of certain documents relating to the decedent's estate, and is acting only as a fiduciary for the estate. If the Surrogate’s Court determines that a Temporary Administrator should be appointed, that person will have an identity of interest with Mr. Horler. Finally, our decision to abstain on Colorado River grounds is influenced, in part, by the special expertise of the Surrogate’s Court in matters related to the probate and administration of wills. Although this case may not fall within the so-called “probate exception” to federal court jurisdiction, since jurisdiction is invoked pursuant to a federal statute rather than diversity of citizenship, Ashton v. Josephine Bay & C. Michael Paul Foundation, 918 F.2d 1065, 1071-72 (2d Cir.1990) (<HOLDING>), abstention is particularly appropriate in

A: holding that in order for a defendant to remove a case to federal court based upon diversity jurisdiction there must be complete diversity of citizenship both at the time that the case is commenced and at the time that the notice of removal is filed
B: holding that in a diversity action a federal court must apply the law of the forum state
C: holding that a federal court in diversity jurisdiction must apply state substantive law
D: holding case for exercise of federal jurisdiction stronger in interpleader action than in diversity action
D.