求大神解Manhattan CR上的一道题

猪智

Manhattan CR上的一道题，实在想不明白为什么选择B。求大神指点迷津：

Student Advisor:
One of our exchange students faced multiple arguments with her parents over the course of the past year. Not surprisingly, her grade point average (GPA) over the same period showed a steep decline. This is just one example of a general truth: problematic famliy relationships can cause significant academic difficulties for our students.

The claim by the Student Advisor would be more properly drawn if which of the following were inserted into the argument as an additional premise?
A. Last year, the exchange students reduced the amount of time spent on academic work, resulting in a lower GPA.
B. The decline in the GPA of the exchange students was not the reason for the students's argument with her parents.
C. School GPA is an accurate measure of a student's intellectual ability
D. If proper measures are not taken, the decline in the student's academic performance may become irreversible.
E. Fluctuations in academic performance are typical for many students.

Answer: B.

除了B之外，其他选项我都知道为什么错了。求问：B为什么是正确的？

我的理解是：
－ 结论是家庭问题造成成绩下降。
－ 要找个Premise要strengthen结论（a － 家庭问题 ----> b － 学生成绩下降），也就是找个选项支持/加强a---->b。
B选项在我看来，充其量只能说明b（学习成绩下降）不是导致a（学生跟家长吵架；家庭问题）的原因，但不能这样不能支持／加强结论（a----->b)啊。。。。

求大神指点。。。。

alzn2765

每天答两题，恭喜中奖。

B的意思就是“因果没有倒置”，定否了因果倒置的可能性自然是加强了Argument。属于defender类assumption的一种。

猪智

alzn2765 发表于 2015-11-1 19:40
每天答两题，恭喜中奖。

B的意思就是“因果没有倒置”，定否了因果倒置的可能性自然是加强了Argument。属 ...

cheers, mate. 第一次碰到这样的的。请举出一个具体的例子好吗？谢谢～

alzn2765

猪智 发表于 2015-11-2 01:42
cheers, mate. 第一次碰到这样的的。请举出一个具体的例子好吗？谢谢～

http://forum.chasedream.com/foru ... ;page=1#pid22217003