The juvenile court had the express statutory discretion to order a juvenile disposition such as a ranch, camp, or Youth Authority, or to impose an adult sentence, where a 15-year old minor with no known prior criminal history pleaded guilty to second degree robbery and admitted personal firearm use on a “discretionary direct file” authorized by Proposition 21. Therefore, where the record showed that the court had no awareness of that discretion, and sentenced the minor to state prison following adult criminal proceedings, remand was required for than exercise of informed judicial discretion. The requirement of Penal Code section 1170.19, subdivision (a)(4) that on a discretionary direct file a court must secure a prosecutor’s consent to order a juvenile disposition violates the state Constitution’s separation of powers doctrine.