The establishment, operation or maintenance of stores by the following shall be exempt from the license tax imposed by this article:
(a) The United States of America, the State of West Virginia and its political subdivisions;
(b) Religious and charitable organizations;
(c) Any person engaged within this City in the business of producing agricultural products who, individually or collectively, sells in such store only agricultural products which he has produced.
(1975 Code Sec. 10-36)