With no explanation, chose the best option from "A", "B", "C" or "D". authority in a resentenc-ing proceeding under § 3582(c)(2) is a question of law that we review de novo.” United States v. Rhodes, 549 F.3d 833, 837 (10th Cir.2008). The government contends that Mr. Mata-Rodriguez is only entitled to plain-error review because he did not first raise his appellate arguments before the district court. However, we need not reach a conclusion on this matter, because even under the standard of review that is more favorable to Mr. Mata-Rodriguez (i.e., abuse of discretion), he cannot prevail. Mr. Mata-Rodriguez’s arguments depend on the contours of the sentence-modification procedure set out in 18 U.S.C. § 3582(c)(2). That procedure is limited and our caselaw has articulated its contours. See United States v. Washington, 759 F.3d 1175, 1181 (10th Cir.2014) (<HOLDING>). The district court, within its discretion,

A: recognizing that the modification procedure set out in  3582c2 is carefully constrained
B: holding that a bid award may be set aside if either 1 the procurement officials decision lacked a rational basis or 2 the procurement procedure involved a violation of regulation or procedure
C: holding that when an agency fails to follow the proper procedure under the illinois administrative procedure act for the adoption of rules the rule is invalid
D: holding that an ineffective grievance procedure bars employers defense based on that procedure
A.