The establishment, operation or maintenance of stores by the following shall be exempt from the license tax imposed by Section 725.03:
(a) The United States of America, the State of West Virginia and its political divisions;
(b) Religious and charitable organizations;
(c) Any person or persons engaged within the City in the business of producing agricultural products, who, individually or collectively, sell in such store only agricultural products which he or they have produced.
(1978 Code Sec. 14-32.)