难题求助牛人

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. The executives claim that the discount programme has been a huge success, since cash register receipts of 50 or more are up thirty percent since the beginning of the programm.

which of the following, if true, most seriously weakens the claim of the red label executives?

A  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

B  Almost all of the people who have begun spending 50 or more at red label since the discount programme began are longtime customers who have increased the average amount of their shopping bills by making fewer trips.

为什么Ａ　不对，不胜感激？

A可以认为是加强。说明原来不来red label 买东西的同志们，因为折扣却来买了。正好支持原因since cash register receipts of 50 or more are up thirty percent since the beginning of the programm。

故而支持结论：The executives claim that the discount programme has been a huge success

同意。