In Vlaardingen you want to turn right into a residential area. A moped rider is riding just behind you and is going straight ahead. You have already started to turn. What do you do?
You turn first, because he comes from behind and not from the front
You let the moped rider go straight on first and turn afterwards
You turn first, because you were the first to start the turn
Explanation
False — You only count oncoming traffic. The duty to let straight-ahead traffic go first also applies to traffic riding (close) behind you, like this moped rider (Book p.110).