(a) Bonds may be issued as various series and issues and shall be on a parity.
(b) Bonds may mature serially or otherwise not later than 50 years after the date on which they are issued.
(c) The bonds may bear no interest or interest at a rate or rates determined in accordance with law.
(d) Rates of interest on bonds may be fixed, variable, floating, adjustable, or otherwise, determined by the board or determined pursuant to any contractual arrangements approved by the board.