单选题 What does the second sentence of Paragraph 2 means?

【正确答案】 A
【答案解析】第二句话For most children,their goals are not set by an internal clock but by the outside world.说明:对大多数孩子来说,他们目标的确定依据外部世界并非依据自身。此句意思与A项相同。