削弱题能反对前提吗？有例题~请帮忙看下谢谢~

fayshi

Metropolis regulation limiting to four days the period during which milk can be sold to consumers after pasteurization is unreasonable. Under optimal conditions, pasteurized milk kept at 40 degree Fahrenheit remains unspoiled for at least 14 days. If Metropolis current limitation were changed to eight days, milk prices would drop, but product quality would be unaffected. Which of the following, if true, would most seriously weaken the conclusion drawn above?
(A) Most consumers keep milk no more than three days after purchase.
(B) A recent survey showed keep that 20 percent of Metropolis consumers favored extending the current limitation on the sale of milk to 8 days.
(C) Metropolis' grocery-store owners would prefer small, frequent deliveries of milk to larger, infrequent deliveries.
(D) Milk kept longer than 14 days after pasteurization generally presents no media dangers if consumed.
(E) In Metropolis, conditions for handling and storing milk after pasteurization are seldom close to optimum.

Key is E

我的问题是，E选项是不是反对了原文的前提？（即文中红字部分）

根据Lawyer说的削弱题不能反对前提，而这题反对前提的明明就是答案啊，很困惑~~

fayshi

我好像有点明白了：如果结论是由一个假设推出的,那么就可以通过WEAKEN这个假设来WEAKEN结论,但是如果文中是一个事实推出的结论,那么就只好想办法WEAKEN结论了.结论中如果带条件句的话，削弱为：IF出现THEN不出现（或）IF条件推不出THEN（或）IF条件不出现 / 出现相反的情况

 

这是我看了前人的一些帖子，和通过几道OG题总结出来的，欢迎大家讨论