6. To entice customers away from competitors, Red Label supermarkets have begun offering discounts on home appliances to customers who spend $50 or more on any shopping trip to Red Label. Red Label executives claim that the discount program has been a huge success, since cash register receipts of $50 or more are up thirty percent since the beginning of the program.
Which of the following, if true, most seriously weakens the claim of the Red Label executives?
(A) Most people who switched to Red Label after the program began spend more than $50 each time they shop at Red Label.
(B) Most people whose average grocery bill is less than $50 would not be persuaded to spend more by any discount program.
(C) Most people who received discounts on home appliances through Red Label’s program will shop at Red Label after the program ends.
(D) Since the beginning of the discount program, most of the people who spend $50 or more at Red Label are people who have never before shopped there and whose average grocery bill has always been higher than $50.（E）
(E) Almost all of the people who have begun spending $50 or more at Red Label since the discount program began are longtime customers who have increased the average amount of their shopping bills by making fewer trips.
原文说To entice customers away from competitors, Red Label supermarkets have begun offering discounts on home appliances to customers who spend $50 or more on any shopping trip to Red Label.假如顾客在它的这种促销手段的激励下纷纷把消费提高到50元以上，那确实是说明该商家成功了，但假如顾客消费一直以来就是大于50元的，那商家的促销手段是否成功就难以判断，所以我觉得答案应该是D，E谈的是收益的问题，购物次数减少*增加的消费额----》收益不变，商家未得利，但问题是原文没有探讨收益问题，它探讨的是商家是否成功将客户吸引到自己门下，不懂为啥是E而不是D，请教！ | 
