With no explanation, chose the best option from "A", "B", "C" or "D". now cannot, through the exercise of its own medical expertise and judgment. Coupled with the lack of a reasons-or-bases requirement at the time of the November 1983 decision, it is, at a minimum, not undebatable that the Board found the October 1982 opinion to be deficient in some way, and the appellant’s arguments amount to a disagreement as to how the Board weighed the evidence of record— something that cannot constitute CUE. See Damrel, 6 Vet.App. at 245; Russell, 3 Vet.App. at 313-14. To be clear, the Court does not hold that it would reach the same result were it reviewing this case on direct appeal. See King, 26 Vet.App. at 442. The Court cannot conclude, however, that the November 1983 Board decision misapplied § 3.310(a). See Kent v. Principi, 389 F.3d 1380, 1384 (Fed.Cir.2004) (<HOLDING>). Therefore, we hold that the Board’s

A: recognizing that appellate court reviews questions of law de novo
B: holding that the proper review for the trial courts application of the law is de novo
C: holding that we review constitutional challenges de novo
D: holding that the court is obliged to review questions of law de novo  in cue challenges
D.