A3 covers the sale of Food & Drink
B7 Covers processes for materials of animal origin and includes 14 different uses. These range from processing potential food stuffs such as the boiling or cleaning of tripe or curing fish to more general processes which nonetheless involve animal products. An example here is producing manure or activities processing “skins” (such as leather).
Both the above are according to Wikipedia.
Perhaps Bargain Booze are thinking of crossing the road.