Section 16. (a) A mutual bank shall have a board of investment consisting of not less than 5 members, who shall be trustees of the corporation. Only 1 of the persons holding the office or performing the duties of president, executive vice president, senior vice president or treasurer shall at the same time be a member of the board of investment. The board shall elect a clerk who may, but need not be, a member of the board. The board of investment may invite 1 or more trustees who are not members of the board to attend its meetings during the monthly, quarterly or semi-annual periods as the board may determine.

(b) At least quarterly, the treasurer or other officer designated by the board of investment shall submit to the board of investment, a written report, over the treasurer or other officer's signature, covering the period for which the report has not yet been submitted.