When an aircraft selects transponder Code 7500, indicating unlawful interference, what is the controller's appropriate response under current PANS-ATM procedures?

1. Give the aircraft priority, monitor and plot its progress, continue transmitting information needed for safe flight, coordinate and notify the designated organizations, and avoid requesting transmissions unless communications remain normal.
2. Broadcast on the public radio frequency that the aircraft has been hijacked by terrorists.
3. Order all flight passengers to wrestle the hijackers immediately.
4. Turn off the ATC radar display.