The custodian shall transfer in an appropriate manner the custodial property to the minor or to the minor’s estate upon the earlier of:
(1) The minor reaches 18 years of age, or if the transfer was made as provided in section 21-309(d), the minor reaches 21 years of age, with respect to custodial property transferred under section 21-304 or 21-305;
(2) The minor reaches 18 years of age with respect to custodial property transferred under section 21-306 or 21-307; or
(3) The minor’s death.