The exemption provided by Section 4005.001 applies to the sale, by the issuer itself or by a registered dealer, of any security either issued or guaranteed by:
(1) the United States;
(2) the District of Columbia, a state, territory, or insular possession of the United States;
(3) a political subdivision of a state of the United States, including a county, city, municipal corporation, district, and authority; or
(4) a public or governmental agency or instrumentality of an entity described by Subdivisions (1)-(3).