(a) The board of supervisors may by ordinance designate that the public administrator is ex officio public guardian.
(b) If the board of supervisors has not designated the public administrator as ex officio public guardian, but has appointed another public guardian, it may terminate the appointment and may by ordinance designate that the public administrator is ex officio public guardian and all authority vests in the successor.
(c) If the public administrator has been designated ex officio public guardian, the board of supervisors may by ordinance terminate the designation and appoint another public guardian and all authority vests in the successor.