The most important educational factor for a child to achieve success in school and life is

The most important educational factor for a child to achieve success in school and life is to______.

A．receive a good and early pre-schooling

B．prolong his or her learning time in school

C．get instruction from more excellent teachers

D．get person-to-person help from the teachers

请帮忙给出正确答案和分析，谢谢！