the court must decide whether, in its discretion, it will impose the newly calculated sentence or retain the original sentence. Id. at 781. The court should make this determination in light of the 18 U.S.C. § 3553(a) factors. Id. A sentencing adjustment pursuant to § 3582(c)(2) is not a de novo resentencing. Id. Where a retroactively applicable Guideline amendment reduces a defendant’s base offense level, but does not alter the sentencing range upon which his sentence was based, the district court is not authorized to grant a sentence reduction pursuant to § 3582(c)(2). Moore, 541 F.3d at 1330. This includes the situation in which a retroactive amendment of § 2Dl.l(c) would result in a lower base offense level, but the defendant was sentenced as a career offender. See id. at 1326-30 (<HOLDING>). In Moore, this court noted that we undertake
holding that while amendment 706 was applica ble to the defendants in question because it reduced their base offense levels a reduction was not authorized because the amendment did not have the effect of lowering their applicable guideline ranges because of the application of the career offender guideline holding a reduction in defendants sentence as a career offender was not authorized under  3582c2 because amendment 706 did not lower his applicable guideline range under the careeroffender guidelines holding that amendment 706 did not have the effect of lowering the applicable guideline range where the defendants received statutory mandatory minimum sentences and thus the defendants were not eligible for relief under  3582 holding that while amendment 706 was applicable to the defendants in question because it reduced their base offense levels a reduction was not authorized because the amendment did not have the effect of lowering their applicable guideline ranges because of the application of the career offender guideline holding that a defendant whose original sentence was based upon the careeroffender guideline and not  2d11 could not receive a sentence reduction based on amendment 706 because it did not have the effect of lowering the applicable guideline range