This subchapter:
(1) Applies only to the following governmental units: The state; and
(2) An agency, board, commission, or instrumentality of the state; and
(3) Does not apply to the following governmental units: A county, municipality, school district, or other political subdivision of the state;
(4) A special assessment or taxing district established under the laws of the state; and
(5) An agency, board, commission, or instrumentality of an entity listed in subdivision (2)(A) or subdivision (2)(B) of this section.