It is a violation of this chapter for any retailer:

A. To allow or permit any alcoholic liquors to be drunk or consumed on his licensed premises;

B. To maintain or keep in close proximity to such licensed premises any place for the consumption of alcoholic liquors purchased from him;

C. To sell any alcoholic liquors at any place other than his licensed premises;

D. Directly or indirectly, or through any subterfuge, to own, operate or control any interest in any wholesale liquor establishment, liquor manufacturing or bottling firm; provided, that this subsection shall not prevent any retailer from owning stock in any corporation which wholesales, manufactures or bottles alcoholic liquors when he owns such stock for investment purposes only. (Prior code § 3-13).