When a motion to modify disposition is filed against a juvenile who was found to be a child engaged in delinquent conduct for an offense enumerated in section 53.045(a) of the code and the original petition was approved by the grand jury, the trial court has two options: either deny the motion to modify and continue the juvenile on probation, or grant the motion to modify and sentence the juvenile to a determinate sentence at TYC. See TEX. FAM. CODE ANN. 54.05(f) (Vernon Supp. 2000); See also id. 53.045(a) (enumerated offenses); id. 54.04(d) (permitted dispositions).