单选题 A study of adults who suffer from migraine headaches revealed that a significant proportion of the study participants suffer from a complex syndrome characterized by a set of three symptoms. Those who suffer from the syndrome experienced excessive anxiety during early childhood. As adolescents, these people began experiencing migraine headaches. As these people approached the age of 20, they also began to experience recurring bouts of depression. Since this pattern is invariant, always with excessive anxiety at its beginning, it follows that excessive anxiety in childhood is one of the causes of migraine headaches and depression in later life.
The reasoning in the argument is vulnerable to criticism on which one of the following grounds?

A、 It does not specify the proportion of those in the general population who suffer from thesyndrome.
B、 It fails to rule out the possibility that all of the characteristic symptoms of the syndrome have a common cause.
C、 It makes a generalization that is inconsistent with the evidence.
D、 It fails to demonstrate that the people who participated in the study are representative of migraine sufferers.
E、 (E) It does not establish why the study of migraine sufferers was restricted to adult participants.

【正确答案】 B

【答案解析】[解析] 对本题推理模式的分析发现，该论述把先出现的事物当作后出现的事物的原因来做出它的结论的，它的结论成立的前提是先后出现的事物不可能具有共同的起因，而文中却没有给出这个前提，因此(B)选项是最佳的答案；(A)、(C)、(D)、(E)均为无关选项。