(a) Any municipality, or any board, commission, or other authority duly established by ordinance of any municipality, or the boards of trustees, respectively, of firemen's relief and pension funds and policemen's pension and relief funds of any municipality, or the board of trustees of any retirement system created by the General Assembly, may invest, in its discretion, any of its funds not immediately needed for its purposes in bonds issued under the provisions of this subchapter.
(b) Bonds issued under the provisions of this subchapter shall be eligible to secure the deposit of public funds.