求助一道削弱题

cyang16

这题题目：去年电话销售量极具增加，为了保持这个增长的优势，MI计划扩大自己电话的产量，同时继续投放大量的产品广告。
类型：削弱
正确答案：尽管零售价格有微弱的降低，但是MI的电话销量还是在去年下降了。

我的理解：这题正确答案直接否定了题目开头给的销量增长，从而达到削弱作用。但是不是说：如果前提是事实，则不可以质疑前提的真实性。那正确答案直接质疑了题目的真实性，是不是错了？
原题：Sales of telephones have increased dramatically over the last year. In order to take advantage of this increase, Mammoth Industries plan to expand production of its own model of telephone, while continuing its already very extensive advertising of this product.

Which of the following , if ture, provides most support for the view that Mammoth Industries cannot increase its sales of telephones by adopting the plan outlined above?

A. Although it sells all the telephones that it produces, MI' share of all telephone sales has declined over the last year.
B. MI 's average inventory of telephones awaiting shipment to retailers has declined slightly over the last year.
C. Advertising has made the brand name of MI 's telephones widely known, but few consumers know that MI owns this brand.
D. MI's telephone is one of three brands of telephone that have together accounted for the bulk of the last year's increase in sales.
E. Despite a slight decline in the retail price, sales of MI's telephones have fallen in the last year.
正确答案是E，该如何理解

cyang16

完全搞懂了！自己把整体与部分弄混了！谢谢点拨！！

teddyteddy

先理清題目的line of reasoning:
題目開頭說明的是整體市場的餅變大了.(fact, 不可質疑它的真實性)
goal of the plan: increase its(the company's) sales

E.雖然此公司的price下降了,但sales卻下降了
  此選項說明了目的無法達成，原因是: 此plan無法說明可以利用此波市場大餅的增長,提升該公司的sales(價格都降了還賣不出去,再繼續打廣告或繼續生產又有何用?)

cyang16

自己顶一下！