Which of the Following Is True of Appreciation Messages

Which of the following is true of appreciation messages?

A) Your appreciation messages should not be focused exclusively on the recipient.
B) Your appreciation message should include exaggerated displays of gratitude.
C) In your appreciation messages, avoid including a rationale for the gratitude.
D) You should send appreciation messages that begin with an expression of thanks.
E) Your appreciation messages should have an informal tone when sent to clients.