(a) Bonds issued by a district must be submitted to the attorney general for examination.
(b) If the attorney general finds that the bonds have been authorized in accordance with law, the attorney general shall approve the bonds. On approval by the attorney general, the comptroller shall register the bonds.
(c) After approval and registration, the bonds are incontestable in any court or other forum for any reason and are valid and binding obligations in accordance with the bonds' terms for all purposes.