(a) The board may borrow money for district obligations.
(b) To secure a loan or line of credit, the board may pledge:
(1) revenue of the district that is not pledged to pay the district's bonded indebtedness;
(2) taxes to be imposed by the district in the next 12-month period that are not pledged to pay the principal of or interest on district bonds; or
(3) district bonds that have been authorized but not sold.
(c) A loan for which taxes or bonds are pledged must mature not later than the first anniversary of the date on which the loan is made. A loan for which district revenues are pledged must mature not later than the fifth anniversary of the date on which the loan is made.