Does a police officer need only reasonable suspicion in the context of investigative traffic stops?

A police officer needs "only reasonable suspicion in the context of investigative traffic stops." United States v. Lopez-Soto, 205 F.3d 1101, 1105 (9th Cir.2000). "Reasonable suspicion is formed by specific, articulable facts which, together with objective and reasonable inferences, form the basis for suspecting that the particular person detained is engaged in criminal activity." Id. (internal quotation marks omitted). We review de novo the district court's determination of whether there was reasonable suspicion. United States v. Arvizu, 534 U.S. 266, 275, 122 S.Ct. 744, 151 L.Ed.2d 740 (2002).