求住prep 1 上的一道削弱题

yanwang1018

Cropscan be traded on the futures market before they are harvested.  If a poor corn harvest is predicted, pricesof corn futures rise; if a bountiful corn harvest is predicted, prices of cornfutures fall.  This morningmeteorologists are predicting much-needed rain for the corn-growing regionstarting tomorrow.  Therefore, sinceadequate moisture is essential for the current crop's survival, prices of cornfutures will fall sharply today.

Which ofthe following, if true, most weakens the argument above?

(A) Cornthat does not receive adequate moisture during its critical pollination stagewill not produce a bountiful harvest.

(B)Futures prices for corn have been fluctuating more dramatically this seasonthan last season.

(C) Therain that meteorologists predicted for tomorrow is expected to extend wellbeyond the corn-growing region.

(D)Agriculture experts announced today that a disease that has devastated some ofthe corn crop will spread widely before the end of the growing season.

(E) Mostpeople who trade in corn futures rarely take physical possession of the cornthey trade.

答案是D， 可是我觉得应该是A 阿，前辈帮帮忙给解释一下拉！ 万谢

sdcar2010

A is not the best answer because we do not know if the pollination stage has passed or not before the much-needed rain. If not, A is not weakener.

D, on the other hand, points out a disease will spread WIDELY to corn crop before the end of the growing season. This would lead to decrease of harvest even if the rain provides adiquate moisture.