5B. (1) There shall be an Executive Board of the Authority consisting of a Chairman and three other members. (2) The Chairman of the Executive Board shall be called the Executive Chairman and he shall be the Chief Executive officer of the Authority. (3) The Executive Chairman and other members of the Executive Board shall be appointed by the Government and shall hold office on such terms and conditions as the Government may determine. (4) If a vacancy occurs in the office of the Executive Chairman or if the Executive Chairman is unable to discharge the functions of his office on account of his absence, illness or any other cause, the Government shall make such arrangement for discharging the functions of the Executive Chairman as it may consider expedient. (5) No act or proceedings of the Executive Board shall be invalid or be called in question merely on the ground of any vacancy in, or any defect in the constitution of, the Executive Board.