prep-cr2中的17题为什么选C不选D？

dehhp

p2-rc      17.   (26864-!-item-!-188;#058&003368)

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

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

(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

(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
求解答～！

atto

同困惑，求解！
此題題幹中提供了兩條邏輯線：1. tall tables attract more customers by affording a better view of the celebrities; 2. customers stay shorter at the tall tables, which allows the restaurant to serve more people during the same amount of time. 兩條線都得出餐廳利潤上升的結論。而答案C, D分別削弱了這兩條線，選其中任何一個都證明另一個也是對的啊？