With no explanation, chose the best option from "A", "B", "C" or "D". the details of the government’s arguments on these grounds. Instead, we hold that Harrison has, by stipulating, waived any right to contest the absence of proof on the stipulated elements. This waiver theory of stipulations has been addressed by a number of our sister circuits, and although the government does not directly advance it in this case, it is necessarily raised by the nature of the appeal. By failing to advance it explicitly, we could perhaps construe the government’s brief as having waived the waiver theory argument, but we will reach the issue because it is squarely presented by this ease and was relied upon by the trial court. See, e.g., United States Nat’l Bank of Or. v. Independent Ins. Agents of Am., Inc., 508 U.S. 439, 445-49, 113 S.Ct. 2173, 124 L.Ed.2d 402 (1993) (<HOLDING>). As the Supreme Court stated in Kamen v.

A: holding that an appellate court has discretion to consider an issue not argued by the parties
B: holding that the court has discretion not to consider an issue abandoned on appeal
C: holding that an appellate court may not consider an issue not presented to the trial judge on appeal from final judgment on the merits
D: holding that an appellate court cannot consider an issue that was not preserved for appellate review
A.