asset class Prescription {…}

interface Pharmacy {
  void depositPrescription(Prescription @ Owned >> Unowned p);  
  Prescription @ Owned removePrescription(Prescription @ Unowned p);
  Prescription @ Unowned getAnyPrescription();
}
 
class Patient {
  void fillPrescription(Pharmacy @ Unowned pharmacy, Prescription @ Unowned pre) {
    pharmacy.depositPrescription(pre); // Location (A)    
    
    Prescription@Unowned pre2 = pharmacy.getAnyPrescription();
    Prescription@Owned removedPrescription = pharmacy.removePrescription(pre2); // Location (B)
    pharmacy.depositPrescription(removedPrescription); // Location (C)
  }
}

For each location where the compiler will give an error, check the corresponding box and explain why there is an error.