No licensee authorized under this chapter to sell alcoholic beverages to wholesalers or retailers shall—

1. (a) Discriminate, directly or indirectly, in price, in discounts for time of payment or in discounts on quantity of merchandise sold, between one wholesaler and another wholesaler, or between one retailer and another retailer purchasing alcoholic beverages bearing the same brand or trade name and of like age and quality;

   [There is no clause (b).]