Which of the Following Concluding Sentences Is Most Likely to Build

Which of the following concluding sentences is most likely to build goodwill in a routine inquiry message?

A) Your prompt reply to our proposal by August 31 will allow us to start our work on time.
B) We would appreciate an early response.
C) We know that you will be kind enough to help us. Thank you in advance.
D) Hoping to hear from you ASAP.
E) Please return the completed project reports at your convenience.