Does the jury have to agree that there was entrapment as a matter of law?

The court instructed the jury on Sher's defense of entrapment, but Sher argues on appeal that the court should have held there was entrapment as a matter of law. To prove entrapment as a matter of law, the defendant must show by undisputed evidence that he was not predisposed to commit the crime, but did so as a result of the government's inducement. United States v. Citro, 842 F.2d 1149, 1151-52 (9th Cir.), cert. denied, 109 S.Ct. 170 (1988); United States v. Marcello, 731 F.2d 1354, 1357 (9th Cir.1984).