Correct!

You've been waiting for some time to make a right turn into a side road. What should you do just before you start turning?

Move close to the kerb
Select a higher gear
Make a lifesaver check
Correct answer
Flash your headlights

DVSA theory test explanation

Remember your lifesaver glance before you start to turn. If you've been waiting for some time and a queue has built up behind you, a vehicle further back may try to overtake. In this situation, it's especially important to look out for other motorcycles, which may be approaching at speed.