(a) The board shall provide written notice of a hearing under this subchapter to the person who is the subject of the proposed disciplinary action not later than the 21st day before the date of the hearing.
(b) The notice must state:
(1) the time and place of the hearing; and
(2) the nature of each charge against the person.
(c) The notice may be served in person or by registered or certified mail to the person's last known address.