A、Disconnect his telephone. B、Call the other party back. C、Blow a whistle into the receiver when answering the call. D、Keep a re

M: I’ve been receiving annoyance calls for two weeks. When I answer the phone, the other party hangs up without saying anything. I’ ve tried everything including blowing a whistle into the receiver.
W: Beginning today, we want you to keep a record of the time each call occurs. This will help us trace the calls. If necessary, the telephone company will contact the police.
Question: What does the woman suggest the man do?