单选题 Which of the following points is NOT included in the passage?

A、 One of the major tasks of education is to discover the most promising students.
B、 In order to teach effectively, educators are requested to lay emphasis on one particular field.
C、 Some subjects have been over-emphasized in public schools.
D、 The progress of the society can not merely rely on inventors.

【正确答案】 B

【答案解析】尽管文中提到了有过分强调某一学科的事实，却并没有说明是为了教之有效这一原因。故选项B不是文章的内容。