Which of the Following Statements Is the Best Closing Statement

Multiple Choice

Which of the following statements is the best closing statement for a claim message?

A) "You must resolve my problem by May 22, or I will report you to the Better Business Bureau."
B) "It would be extremely difficult for me to recommend you to others after this incident."
C) "I would be thankful if you could solve this problem by Monday."
D) "On the basis of my experience with your inferior product, I demand a refund."
E) "You have been extremely disappointing in meeting your claims of prompt delivery."