Correct!

You're driving your car. When may you use a hand-held mobile phone?

When you're receiving a call
When you've parked safely
Correct answer
When you're driving at less than 30 mph
When your car has automatic transmission

DVSA theory test explanation

It's illegal to use a hand-held mobile phone while you're driving, except in a genuine emergency. Even using a hands-free kit can distract your attention. Park in a safe and convenient place before receiving or making a call or using text messaging. Then you'll also be free to take notes or refer to papers.