Interest; maturity; form; method of sale.

A. Revenue bonds issued under the provisions of the Water and Sanitation District Act shall bear interest at not to exceed six percent per year, payable annually or semiannually, shall be payable at the option of the district, at the end of ten years from the date thereof; and due by their terms in not more than twenty years from date hereof; as determined by the district, shall be serial in form and maturity and numbered from one upward, consecutively, or may consist of one bond payable, at one time or in installments, and shall be sold for cash, at not less than par, and at either public or private sale. B. All prior revenue bond issues of districts where one bond was issued in lieu of multiple bonds are validated.