A.R.S. § 14-5203

A minor of fourteen or more years may prevent an appointment of his testamentary guardian from becoming effective, or may cause a previously accepted appointment to terminate, by filing with the court in which the will is probated a written objection to the appointment before it is accepted or within thirty days after notice of its acceptance. An objection may be withdrawn. An objection does not preclude appointment by the court in a proper proceeding of the testamentary nominee or any other suitable person.