With no explanation, chose the best option from "A", "B", "C" or "D". true here. Our decision in United States v. Murillo, 255 F.3d 1169 (9th Cir.2001), does not require a different result. Murillo did not involve expert testimony about the struc ture of drug trafficking organizations. Rather, Murillo involved “unknowing drug courier” modus operandi testimony — expert testimony that drug traffickers do not routinely entrust large quantities of drugs to people who are unaware that they are transporting them. Id. at 1176. In that case, we held that “unknowing drug courier” testimony was admissible in a drug possession case involving over one million dollars worth of methamphetamine and cocaine to attack the defendant’s defense that he was “simply an unknowing courier.” See id. at 1176-77; see also United States v. Campos, 217 F.3d 707, 712 (9th Cir.2000) (<HOLDING>); United States v. Cordoba, 104 F.3d 225, 230

A: holding a fiveyear old drug conviction is probative of a defendants state of mind in a drug conspiracy case
B: holding that unknowing drug courier testimony was admissible in a complex drug importation case
C: holding that evidence of defendants recruitment of single drug courier was sufficient to support section 3b11c enhancement
D: holding prior drug deals admissible to prove knowledge of the drug trade
B.