单选题 Normally, increases in the price of a product decrease its sales except when the price increase accompanies an improvement in the product. Wine is unusual, however. Often increases in the price of a particular producer's wine will result in increased sales, even when the wine itself is unchanged.
Which of the following, if true, does most to explain the anomaly described above?

A、 The retail wine market is characterized by an extremely wide range of competing products.
B、 Many consumers make decisions about which wines to purchase on the basis of reviews of wine published in books and periodicals.
C、 Consumers selecting wine in a store often use the price charged as their main guide to the wine's quality.
D、 Wine retailers and producers can generally increase the sales of a particular wine temporarily by introducing a price discount.
E、 (E) Consumers who purchase wine regularly generally have strong opinions about which wines they prefer.

【正确答案】 C

【答案解析】[解析] 本题为解释反常变化，要抓住反常变化的关键点——价格来定位选项，根据“直接”的原则，(C)能很好地起到实现问题目的的作用。(D)易误选，但(D)与段落的“价格上升”相违背，所以(D)不对。