With no explanation, chose the best option from "A", "B", "C" or "D". Or they could have asked the district court to strike the defense, and mustered arguments at. that time in favor of exclusive federal jurisdiction. The difficulty for the Davises was compounded by the fact that no court, so far as I can tell, had ever held that RCRA cases could be brought in state court, and that numerous courts had either held or assumed that jurisdiction was exclusively federal. Nor do we find any report of a RCRA citizen action ever being brought in an Ohio court. The district court’s holding on this matter is at least plausible, but I cannot say that resolution of that question is sufficiently plain under Yellow Freightand Holmes to have put the Davises fairly on notice that they could bring the RCRA allegation in Ohio court. See Diversified Foods, 985 F.2d at 31 (<HOLDING>) Indeed, if the district court held strong

A: holding that federal courts have exclusive jurisdiction over securities act class actions
B: recognizing that a goodfaith belief in exclusive federal jurisdiction might excuse a failure to bring a federal claim as part of a previous statecourt action but rejecting that excuse where the belief in exclusive federal jurisdiction was formed in the face of two circuit decisions to the contrary
C: holding that federal jurisdiction over rico claims is concurrent and not exclusive
D: holding that the state law of preclusion must be followed even when federal jurisdiction over the subject matter of a claim is exclusive
B.