到底C还是D是正确答案?GMAT GWD一道争议题,求官方答案,不是你的个人理解就好的.重奖!

到底C还是D是正确答案?GMAT GWD一道争议题,求官方答案,不是你的个人理解就好的.重奖!
Companies that must determine well
in advance of the selling season how
many unites of a new product to manu-
Line facture often underproduce products
(5) that sell well and have overstocks of
others.The increased incidence in
recent years of mismatches between
production and demand seems ironic,
since point-of-sale scanners have
(10) improved data on consumers’ buying
patterns and since flexible manufac-
turing has enabled companies to
produce,cost-effectively,small
quantities of goods.This type of
(15) manufacturing has greatly increased
the number of new products introduced
annually in the United States.However,
frequent introductions of new products
have two problematic side effects.For
(20) one,they reduce the average lifetime of
products; more of them are neither at the
beginning of their life (when prediction
is difficult) or at the end of their life
(when keeping inventory is expen-
(25) sive because the products will soon
become obsolete).For another,as
new products proliferate,demand is
divided among a growing number of
stock-keeping units (SKU’s).Even
(30) though manufacturers and retailers can
forecast aggregate demand with some
certainty,forecasting accurately how
that demand will be distributed among
the many SKU’s they sell is difficult.
(35) For example,a company may be able
to estimate accurately the aggregate
number of shoes it will sell,but it may
be uncertain about which specific
types of shoes will sell more than
other types.
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Q23:(C or 我看到CD有说D是正确答案,我的这套GWD说是C是正确答案）
Which of the following most accurately describes the function of the last sentence in the passage (lines 35-40)?
a.To cite a situation in which the aggregate demand is more important than the distribution of demand among SKU’s
b.To refute an assertion about the side effects of flexible manufacturing
c.To illustrate an assertion about companies’ ability to forecast demand
d.To provide an example of ways in which companies address the difficulties of forecasting demand
e.To note an exception to the author’s assertion about distributing demand among SKU’s
请回答的同学cite官方的答案网页或者什么，网上讨论的什么不算，这个我也看过了。但是当年prep给的是D.