With no explanation, chose the best option from "A", "B", "C" or "D". when its jurisdiction is “in doubt,” because to do so would “carr[y] the courts beyond the bounds of authorized judicial action.” Steel Co. v. Citizens for a Better Envt., 523 U.S. 83, 101, 94, 118 S.Ct. 1003, 140 L.Ed.2d 210 (1998). At the same time, the Court has recognized that “in cases removed from state court to federal court, as in cases originating in federal court, there is no unyielding jurisdictional hierarchy,” Ruhrgas, 526 U.S. at 578, 119 S.Ct. 1563 and a court need not make a difficult determination as to subject matter jurisdiction when another clear threshold defect would warrant “denying audience to a case on the merits.” Sinochem Int’l Co. v. Malaysia Int’l Shipping Corp., 549 U.S. 422, 431, 127 S.Ct. 1184, 167 L.Ed.2d 15 (2007) (internal quotation marks omitted) (<HOLDING>). “It is hardly novel for a federal court to

A: holding that a district court has discretion to grant a defendants forum non conveniens motion to transfer before disposing of any other threshold challenges
B: holding that  1404a governed a forum non conveniens motion to transfer based upon a forum selection clause despite the current forums public policy that may refuse to enforce such provisions
C: holding that a permissive forum selection clause containing a waiver of any claims of forum non conveniens amounts to a mandatory forum selection clause at least where the plaintiff chose the designated forum
D: holding that issue concerning forum non conveniens decision was not suitable for interlocutory appeal in part because a forum non conveniens decision is inherently factsensitive
A.