Which of the following, if true, most seriously weakens the researcher's conclusion?

(A)          After becoming addicted to drugs, drug addicts learn to manipulate other people as a way of obtaining drugs.

(B)         When they are imprisoned, drug addicts often use their ability to manipulate other people to obtain better living conditions.

(C)         Some nonaddicts manipulate other people more than some addicts do.

(D)         People who are likely to become addicts exhibit unusual behavior patterns other than frequent manipulation of other people.

(E)         The addicts that the researcher studied were often unsuccessful in obtaining what they wanted when they manipulated other people.

答案是A, 我感觉D也是削弱. 而且比A好, 谁能指点一下?

同意楼上。结论说控制他人的易上瘾，削弱就说其实是上了瘾才去控制他人（以获得毒品）因果倒置是常考的一种削弱方式。题干说A是B的原因，削弱就说B是A的原因。D是无关，因为本文题说的是控制行为，而不是其它的或是反常的行为。