Which of the following is TRUE of teacher’s correction of his student’s writing errors？ （

Which of the following is TRUE of teacher’s correction of his student’s writing errors？ ()

A．It is good to correct all the errors

B．A teacher should write something on the papers to encourage his students

C．A teacher’s handwriting must be tidy and clear

D．A teacher had better point out the way for each student to improve his writing

请帮忙给出正确答案和分析，谢谢！