(单选题)

What does Cain think of the difference between introverts and extroverts? ( )

A.It is biological

B.It is ideological

C.It is statistical

D.It is psychological.

参考答案：D

参考解析：

细节题。根据关键词introverts and extroverts定位至第三段 This has everything to do with how our brains are wired, how our nervous systems react to stimulation. In other words, introverts have a low threshold for dopamine, so they are easily overwhelmed. In contrast, extroverts have a very high threshold so can keep going for longer.可知这两个群体间的区别在于本身的多巴胺数量，属于心理差异。选项A：生物科学；选项B：意识形态，排除；选项C：统计学，排除；选项D：心理学。故本题正确答案选D。

知识点：细节题英语阅读理解通用英语