请教 OG 10 综合中的CR第48题

48. 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 does not cause people’s immune-system activity to decrease.
   

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

OG解释 判断D选项的否题 mental illness can depree immene-system activity ,为错误,则D为正确选项,

能解释下为什么吗?

LAWYER 类型分类中ASSUMPTION 的方法包括:A 不是其他原因或可能导致该结果  B 结合因果:或有因有果或元果元因 C因果没颠倒    D 显示因果关系的资料是准确.

这道题是属于哪种呢?

谢谢!

OG答案解释判断D的否命题" mental illness can depress immune-system activity",为错误则说明D为正确答案。

能解释下为什么吗？

LAWYER的方法中说ASSUMPTION题型方法包括：A 不是其他原因或可能导致该结果 

B 结合因果：或有因有果或无果无因              C 因果没颠倒             D 显示因果关系的资料是准确。

这一题是属于哪一种呢？

谢谢

请求帮助啊~~