根据下面内容，回答171-175题Every product on the market has a variety of costs built into it before it is ever put up for saleto a customer．There are costs of production, transportation, storage, advertising, and more．Eachof these costs must bring in some profit at each stage : truckers must profit from transporting prod-ucts, or they would not be in business．Thus, costs also include several layers of profits．The sell-ing price of a product must take all of these costs (and built in profits) into consideration．The sell-ing price itself consists of a markup over the total of all costs, and it is normally based on a per-centage of the total cost.The markup may be quite high,90 percent of cost, or it may be low．Grocery items in a su-permarket usually have a low markup, while mink coats have a very high one．High markups,however, do not in themselves guarantee big profits．Profits come from turnover．If an item has a50 percent markup and does not sell, there is no profit．But if a cereal has an 8 percent markupand sells very well, there are reasonable profits.While most pricing is based on cost factors, there are some exceptions．Prestige pricing meanssetting prices artificially high in order to attract select clientele．Such pricing attempts to suggestthat the quality or style of the product is exceptional or that the item cannot be found elsewhere.Stores can use prestige pricing to attract wealthy shoppers.Leader pricing and bait pricing are the opposites of prestige pricing．Leader pricing meanssetting low prices on certain items to get people to come into the stores．The products so priced arecalled loss leaders because little or no profit can be made on them．The profits are made from otherproducts people buy while in the store．Bait pricing, now generally considered illegal, means set-ting artificially low prices to attract customers．The store, however, has no intention of sellinggoods at the bait prices．The point is to get people into the store and persuade them of the inferior-ity of the low priced item．Then a higher priced item is presented as a better alternative.A common retail tactic is odd priced products．For some products of $300, the store will setthe price at $295 or $299.95 to give the appearance of a lower price．Automobiles and other highpriced products are usually priced in this manner．For some reason $7995 has more appeal to apotential car customer than $8000.Bid pricing is a special kind of price setting．It is often used in the awarding of governmentcontracts．Several companies are asked to submit bids on a job, and normally the lowest bidderwins．A school system may want to buy a large number of computers．Several companies are askedto submit prices, and the school district will decide on the best bid based as well on considerationsof quality and service. Odd-pricing method（）

A. is often used with very expensive items
B. is only effective on potential car customers
C. is the most popular way of pricing a product
D. is the most effective way of selling low priced products