新prep cr2 75 122求助！

Which of the following, if true, most logically completes the reasoning in the passage?

Kernland’s government restricts the export of unprocessed cashew nuts in order to ensure a low-cost supply for domestic processing plants.Though the policy constrains farm income and limits the number of farmers who can profitably grow cashews, the government defends it on the grounds that, since the processing plants are in urban areas, removing the restrictions would hurt efforts to reduce urban unemployment.However, the policy may actually have contributed to urban unemployment, since __________.

A. a lack of profitable crops is driving many small cashew farmers in Kernland off their land and into the cities
B. some of the by-products of cashew processing are used as raw materials by other industries located in Kernland’s cities
C. the government does not place similar restrictions on the export of any crop other than cashews
D. the income earned by workers in the processing plants is generally greater than that earned by agricultural laborers in rural areas
E. without governmental aid in some form, Kernland’s cashew processing plants would not be able to compete for sales in world markets

答案是A，不太明白A和原文的逻辑关系啊，哪位大牛可以帮忙解释一下？谢谢！！

122.    (26360-!-item-!-188;#058&001881)    (GWD 1-Q40)

Until now, only injectable vaccines against influenza have been available.  arents are reluctant to subject children to the pain of injections, but adults, who are at risk of serious complications from influenza, are commonly vaccinated.  A new influenza vaccine, administered painlessly in a nasal spray, is effective for children.  However, since children seldom develop serious complications from influenza, no significant public health benefit would result from widespread vaccination of children using the nasal spray.
Which of the following is an assumption on which the argument depends?
A. Any person who has received the injectable vaccine can safely receive the nasal-spray vaccine as well.
B. The new vaccine uses the same mechanism to ward off influenza as injectable vaccines do.
C. The injectable vaccine is affordable for all adults.
D. Adults do not contract influenza primarily from children who have influenza.
E. The nasal spray vaccine is not effective when administered to adults.

这道题我认为应该选E啊，答案是D,可是题目已经说了大人不会从小孩哪里感染因为大人只会从COMPLICATIONS中感染，而小孩不会发展处COMPLICATIONS--而E选项就排除了大人可以用nasal来预防流感，因为大人可用Nasal spray的话，这个也是可能会带来significant results的，各位大牛帮忙看看这两道题啊！！！感激不尽！！！

The conclusion of the passage is:
No significant public health benefit would result from widespread vaccination of children using the nasal spray.

This is a necessary assumption question. Use negation.

If you negate E), you have:
The nasal spray vaccine IS effective when administered to adults.
If so, does the conclusion still holds? Yes. The conclusion does not care about vaccination of adults.

On the other hand, if you negate D), you have:
Adults do contract influenza primarily from children who have influenza.
If this is the case, then vaccination of children would prevent the adults from catching the disease. Does the conclusion still holds? No. Bingo. D) is the necessary assumption.