What does the passage mainly discuss？A．The importance of family economic conditions to kid

What does the passage mainly discuss？

A．The importance of family economic conditions to kids" success in study and life.

B．The achievement gap between children from wealthy families and poorer ones.

C．Some countries having achieved success in erasing the gap between children completely.

D．How to narrow the achievement gap between kids from different family backgrounds.

请帮忙给出正确答案和分析，谢谢！