Rodolfo Llanas-Garcia (Lianas) appeals the 51-month prison sentence imposed upon his guilty plea to assaulting a federal agent causing bodily injury while the agent was performing his official duties, in violation of 18 U.S.C. § 111(a)(1) and (b). We AFFIRM.

Lianas contends, for the first time on appeal, that his sentence should be vacated because the district court did not articulate any of the factors set forth in 18 U.S.C. § 3553(a) to the facts of his case, thus failing to exercise or to show that the court exercised its discretion. The plain-error standard of review is applicable. See United States v. Izaguirre-Losoya, 219 F.3d 437, 440-42 (5th Cir. 2000).

Under the discretionary sentencing scheme established by United States v. Booker, 543 U.S. 220, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005), district courts retain the duty to consider the Sentencing Guidelines along with the sentencing factors set forth in § 3553(a). United States v. Mares, 402 F.3d 511, 518-19 (5th Cir.), cert. denied, — U.S.-, 126 S.Ct. 43, 163 L.Ed.2d 76 (2005). Lianas’s sentence is within the guideline range and is presumptively reasonable. See United States v. Alonzo, 435 F.3d 551, 553-55 (5th Cir. 2006). We infer in our reasonableness review that the district court considered the § 3553(a) factors, including Lianas’s history and characteristics, in imposing sen *281 tence. See Alomo, 435 F.3d at 554. Consequently, Llanas is not entitled to relief on grounds of plain error. See Izaguirre-Losoya, 219 F.3d at 440-42.

AFFIRMED.