Correct!

You're following a large vehicle. Why should you stay a safe distance behind it?

You'll be able to corner more quickly
You'll help the large vehicle to stop more easily
You'll give the driver a chance to see you in their mirrors
Correct answer
You'll keep out of the wind better

DVSA theory test explanation

If you're following a large vehicle but are so close to it that you cannot see its exterior mirrors, the driver will not be able to see you. Keeping well back will also allow you to see the road ahead by looking past the large vehicle.