请教紫皮OG逻辑第7题

A researcher discovered that people who have low levels of immune-system activity tend to score much lower on tests of mental health than do people with normal or high immune-system activity. The researcher concluded from this experiment that the immune system protects against mental illness as well as against physical disease.

The researcher’s conclusion depends on which of the following assumptions?

A: High immune-system activity protects against mental illness better than normal immune-system activity does.

B: Mental illness is similar to physical disease in its effects on body systems.

C:  People with high immune-system activity cannot develop mental illness.

D: Mental illness dies not cause people’s immune-system activity to decrease.

E:  Psychological treatment of mental illness is not as effective as is medical treatment.

答案选D，可我个人觉得B是正确的，哪位好心人帮我解释一下，谢谢了！

D

because there is a flaw in the assertion that the author assumes the low immune system causes the mental illness,but that is groundless.what if the mental illness is the real cause of the low immune system? so the answer should rull out the former possibility ,then the assumption made by the author is correct!(*^__^*) 嘻嘻……

B: Mental illness is similar to physical disease in its effects on body systems.

题干的中心词是immune-system  和mental illness

而B说body systems, 并不是题干的内容, 所以属于无关选项

Thanks.

From the experiment we can say that the immune-system activity and the mental health have a kind of relation. But we don't know whether the immune-system activity causes the mental health or the mental health causes the immune -system activity. Only when the latter one is eliminated, can we get the conclusion.

Is that right?