The "Prophet"

In this April 1, 1972, Watchtower it asks, "Does Jehovah have a prophet to help them, to warm them of dangers and to declare things to come?. The question can be answered in the answer in the "affirmative". 

Then it asks, who is this prophet and the answer is "Jehovah's Witnesses.

They go on to say, "Of course it is easy to say that this group acts as a "prophet" of God.  It is another thing to prove it. The only way this can be done is to review the record.  What does it show?