What must you do in case of a traffic jam in a tunnel?

Your answer was correct because in the event of a traffic jam in a tunnel, you must switch on your hazard warning lights to alert other drivers of the situation. Additionally, maintaining a safety distance of approximately 5 meters from the vehicle ahead is crucial for safety in case of sudden movements. This combination follows the regulations for driving safely in tunnels, ensuring both visibility for other drivers and enough space to react in emergencies. Leaving your vehicle immediately is not advised unless there is a clear and immediate danger, as remaining in your vehicle can often be safer.