Which of the following best represents the order from a harsh command to a very polite req

Which of the following best represents the order from a harsh command to a very polite request？ a.Could you close the door？ b.Close the door. c.Please close the door, d.Would you please close the door.

A.b-c-a-d

B.d-a-c--b

C.c-b-a-d

D.c-b-d-a

请帮忙给出正确答案和分析，谢谢！