Sorry if this is late but the answer is B
Answer:
In my opinion, it could be D.
C is wrong just by using common sense, B and A doesn't make much sense either. But D seems reasonable.
Answer: D
The answer is D because the information following "message" is the message. A colon is appropriate (as used in D) when the information after the colon describes or represents the word or phrase that comes before the colon.
