问一道PREP上别人笔记写的弱智题~我好象有个点没懂

At present the Hollywood Restaurant has only standard-height tables.  However, many customers come to watch the celebrities who frequent the Hollywood, and they would prefer tall tables with stools because such seating would afford a better view of the celebrities.  Moreover, diners seated on stools typically do not stay as long as diners seated at standard-height tables.  Therefore, if the Hollywood replaced some of its seating with high tables and stools, its profits would increase.

The argument is vulnerable to criticism on the grounds that it gives reason to believe that it is likely that

喜欢长腿的，因为视线好，可以看名人，但是呆的时间不比普通的长。换成长腿的可以赚钱

(A) some celebrities come to the Hollywood to be seen, and so might choose to sit at the tall tables if they were available 有需求，加强

(B) the price of meals ordered by celebrities dining at the Hollywood compensates for the longer time, if any, they spend lingering over their meals

(C) a customer of the Hollywood who would choose to sit at a tall table would be an exception to the generalization about lingering注意，这里的generalization指的也是坐高凳子的

(D) a restaurant's customers who spend less time at their meals typically order less expensive meals than those who remain at their meals longer

(E) with enough tall tables to accommodate all the Hollywood's customers interested in such seating, there would be no view except of other tall tables 没有view不会减少利润，至少有部分高凳子还是可以赚钱的

垃圾题目：

这题应该这样理解：原文第一句话：这个餐厅的顾客很多是来这里看名人的，因为很多名人经常来这里吃饭。因此，这些顾客想要高一点的台和凳子，因为这样可以把名人看得更仔细。第二句：按照一般的餐饮惯例，坐高凳和高台的人逗留时间比坐标准凳和台的人的时间短，也就是翻台率高点。（这里多点坐高凳的，收 入就会更高。）问题要我们找这个推理的错误。

C就指出了这个错误：（即使按照一般的餐饮惯例，坐高凳和高台的要留时间短一点，）但是这条惯
        例在来好莱坞这里吃饭的人身上不成立。言外之意就是说，来好莱坞这里吃饭的人，坐高凳的合高台的时间起码不必标准凳的短，所以翻台率不会因为换了高台和高
        凳就增加，利润也不会因此增加

别人是这样分析的,可是我觉得D也可以啊~我想问下,如果要求削弱,那么是要证明"结论完全不成立/一定不成立"还是要"结论可以不成立/结论不一定成立"?就像这里,如果说D中说的,因为原文条件中说坐高凳子的人吃饭时间短,那D现在说吃的时间少,点的钱少,所以总的收入利润不一定上去的~不也可以么?请指点!

D说吃饭时间短的客人要比吃饭时间长的客人吃的便宜。我觉得这个选项虽然能够反驳文章观点，但是并没有把桌子凳子这个因素加入，即没有反驳文章的主要矛盾点，这个选项是把“吃饭时间”和“多赚钱”联系在一起。题目是说“换成高桌子”推出“多赚钱”。C说做高桌子凳子的客人也可能be an exception to the generalization about lingering，更好的反驳了文章观点。

仅本人观点，欢迎拍我啊