A study of marital relationships in which one partner's sleeping and waking cycles differ from these of the other partner reveals that such couples share fewer activities with each other and have more violent arguments than do couples in a relationship in which both partners follow the same sleeping and waking pattens.Thus , mismatched sleeping and waking cycles can seriously jeopardize a marriage .

which of the following , if true ,most seriouly weakens the argument above ?

(A) Married couples in which both spouses follow the same sleeping and making pattens also occasionly have arguments that can jeopardize the couple's marriage.

(B) The sleeping and waking cycles of individual tend to vary from season to season

(C) The individuals who have sleeping and waking cycles that differ significantly from these of their spouses tend to argue little with colleagus at work

(D) People in unhappy marriages have been found to express hostility by adopting a different sleeping and waking cycle from that of their spouses

(E) According to a recent study , most people's sleeping and waking cycles can be controlled and modified easily.

答案是D~我选了A。我觉得A取反后是支持原文的，不就是削弱了吗，为什么选D呢？