Incorrect!

You're driving at night on an unlit road. What should you do if you're following another vehicle?

Flash your headlights
Use dipped headlights
Correct answer
Switch off your headlights
You selected this answer
Use full-beam headlights

DVSA theory test explanation

If you follow another vehicle with your headlights on full beam, they could dazzle the driver. Leave a safe distance and make sure that the light from your dipped beam falls short of the vehicle in front.