If there is a market outcome in which the marginal benefit to consumers of the last unit produced is equal to its marginal cost of production, and consumer surplus plus producer surplus is maximized, then A) maximum deadweight loss occurs. B) economic efficiency is achieved. C) profits are maximized. D) costs are minimized.

An allergy products superstore buys 6000 of their most popular model of air filters each year. the price of the air filters is $18. the cost of ordering and receiving shipments is $12 per order. accounting estimates annual carrying costs are 20% of the price. the supplier lead time is 2 days. the store operates 240 days per year. each order is received from the supplier in a single delivery. there are no quantity discounts. what is the store’s minimum total annual cost of placing orders & carrying inventory?