(a) If a school district's application for guarantee of district bonds by the corpus and income of the permanent school fund as provided by Subchapter C is rejected, the district may apply under this subchapter for credit enhancement of bonds described by Section 45.054 by money appropriated for the Foundation School Program, other than money that is appropriated to school districts specifically:
(1) as required under the Texas Constitution; or
(2) for assistance in paying debt service.
(b) The same school district bonds may not benefit under both Subchapter C and this subchapter.
(c) Notwithstanding any amendment of this subchapter or other law, the credit enhancement provided under this subchapter for school district bonds remains in effect until the date those bonds mature or are defeased in accordance with state law.