The author gave his uncles example to______.A．show the fact that education in poor areas i

The author gave his uncles example to______.

A．show the fact that education in poor areas is unexpectedly difficult

B．demonstrate that teacher is not the only factor affecting students" performances

C．prove that he has deep understanding in the education matter

D．illustrate that teachers should be located where they could best perform

请帮忙给出正确答案和分析，谢谢！