A study of marital relationships in which one partner's sleeping and waking cycles differ from those 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 patterns. Thus, mismatched sleeping and waking cycles can seriously jeopardize a marriage.
Which of the following, if true, most seriously weakens the argument above?
去掉occationally只是说明了patterns相同的couple也jeopardize marriage。不能weaken "mismatched patterns jeopardize marriage" 如果原文说mismatched patterns jeopardize marriage more than same patterns,那是weaken。