Any person, firm, corporation or association engaged in selling new or used automobiles or trucks to the public shall be guilty of a Class 2 misdemeanor unless, in any printed advertisement or printed offer in which a price is stated, the following is included: (a) the make, year, and model of such automobile or truck; (b) if reference is made to items of optional equipment which are not included in the advertised price, the additional cost of each such items of optional equipment; and (c) if the manufacturer’s suggested retail price is stated, whether such price is an F.O.B. factory or delivered price.