(a) It shall be the duty of the Board of Selectmen to keep an official record of its proceedings which shall be open for public inspection under State statutes.

(b) The minutes of each meeting shall be approved by the selectmen and shall be filed in the Town Clerk's office and Town Manager's office, a duly certified copy of such minutes, attesting to the accuracy and recording thereof, shall constitute the official transcript of such meeting and shall constitute prima facie evidence of the conduct thereof and the action taken thereat.