A vehicle-system warning buzzer sounds unexpectedly while the bus is carrying passengers. What should the driver do?

1. Continue to the next terminus if the gauges look normal, then enter the warning in the defect log
2. Silence or reset the alarm while moving and delay stopping unless vehicle performance changes
3. Ask another crew member to identify the warning while the driver maintains the scheduled speed
4. Stop at a suitable safe place, secure the passengers and follow the approved warning procedure