一道让我对assumption与support区别有疑问的CR，万分痛苦，求助

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Adoption agency representative: It is true that eight of our last ten babies have been placed with parents who were personally acquainted with at least one of our staff members before initiating the adoption process. However, there is no truth to the accusation against us of favoritism; our decisions have been guided solely by the best interests of the children. Indeed, all ten babies' new parents far surpassed the adoption criteria set both by the law and by our own policy.


Which of the following is an assumption on which the representative's argument depends?


(A) The agency's prior placements of babies with parents who were previously acquainted with its staff have not, in general, been more successful than those with parents unacquainted with the staff.


(B) Of those prospective parents who substantially surpassed the criteria for adoption, most were personally acquainted with agency staff before beginning the application process.


(C) For a time period equal in duration to that during which the data were collected, the average number of babies placed by the agency is close to ten.


(D) Most prospective parents who apply to adopt babies do not meet the agency's criteria for adoption.


(E) The agency will only place babies with parents who not only meet the legal and institutional criteria for adoption, but who in fact surpass those criteria.
答案是B。

看过RON的逻辑课，楼主的理解是：如果选择支持 加强，我毫不犹豫的选B。可是这道是assumption，而且调查中的十个BABY是随机选的，就算B不成立，claim也不是绝对错。我举个栗子：
1000个候选人中，500个人成功收养了小孩，200个人认识员工，800个不认识员工。认识员工又成功收养的只有30个。  那么整体候选人的成功率是0.5，而在有关系的候选人中成功率只有0.15，是远远低于整体成功率的。  这组数据不满足B，可也不能说明”机构的选择不受关系户影响“这个结论就必错吧。假设的定义不是 假设不成立，结论一定错吗？
感觉我把问题想复杂了，可是确实没办法扔掉这种想法：就是假设题跟支持题还是有差别的。
现在被这道题卡了一天，拜托大神们帮我看看这道题吧，万分感谢！！！！！！


最后附上曼哈顿的解释：(B) CORRECT.For the argument to establish lack of bias toward certain applicants, the proportion of "previously acquainted" people among those applicants chosen for placement must reflect the corresponding proportion among all applicants. In other words, if eight out of the ten parents actually chosen were personally acquainted with the staff, then a similar majority of all applicants should have been similarly acquainted with the staff. Alternatively, use the negation test. If this statement is false, then the majority of qualified applicants were in fact unacquainted with agency staff – a situation in which the placement of eight of ten babies with personally acquainted applicants is a clear signal of bias. Since the negation of this statement defeats the argument, the original statement must be assumed.

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拿个小板凳坐等大神们的解疑
我自己顶顶先

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Premise1: 10个里面有8个babies被收养所的认识人领养了。
Premise2: 所有10个收养babies的家庭远远优于法律规定收养标准和收养所的标准。
Conclusion：我们收养所是本着for the best interest of the babies，我们没有favoritism

Gap: 仅仅“远远优于法律规定收养标准和收养所的标准” 就是 "for the best interest of the babies" 吗？不一定。如果所有candidate applicant families都是什么企业财团董事长、政界精英之类，那收养所认识的那些普通人再厉害，条件也不如这些社会精英。因此也不符合 "for the best interest of the babies"而是带有了favoritism

那有种方法使这种可能性不存在，就是让“远远优于法律规定收养标准和收养所的标准” 等于 "for the best interest of the babies"。啥叫"for the best interest of the babies"？就是被选中的parents就是所有prospective parents里面最好的。

楼主说得对，此题有问题。

曼哈顿的解释也是有问题的，“Alternatively, use the negation test. If this statement is false, then the majority of qualified applicants were in fact unacquainted with agency staff – a situation in which the placement of eight of ten babies with personally acquainted applicants is a clear signal of bias.”
破折号后面的理论明显是错的，如果有100个“远远优于法律规定收养标准和收养所的标准” 的candidates，8个最优秀的candidates恰巧staff都认识，而那后面的92个staff不认识，也完全可以成立阿。

题目是问必要条件的，B选项我也觉得不是必要。要是Strengthen的话就对了。

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又看了一遍题目，发现我理解有点错误，是只有10个收养成功的父母，可是依然坚持我的观点。     再举个例子：100个人里面选出10个能吃辣的，其中8个是女生，2个是男生，有人认为女生比男生更能吃辣，专家反驳，认为性别不影响。   如果这100个人里大部分都是女生，确实加强了专家的结论，可是就算男女各50个人也不能说明专家错，很有可能这10个人都是湖南来的所以有吃辣的习惯，而不是性别影响的。 所以女比男多这一条件作不成假设。