In assessing the substantive reasonableness of the sentence, the 10th presumes the sentence to be reasonable because it was within the guideline range for the offense. Under 18 U.S.C. § 3565(a)(2), the 10th explains, a d. ct. has the authority to revoke probation and resentence the defendant under the subchapter related to the original offense conduct. So the d. ct. could ignore the guidelines for Grade C violations.