Correct!

What should you do if your motorcycle breaks down while you're riding through a tunnel?

Switch on hazard warning lights
Correct answer
Remain on your motorcycle
Wait for the police to find you
Rely on CCTV cameras seeing you

DVSA theory test explanation

If your motorcycle breaks down in a tunnel, it could present a danger to other traffic. First switch on your hazard warning lights and then call for help from an emergency telephone point. Do not rely on being found by the police or being seen by a CCTV camera.