At dusk you approach a roundabout alongside the N31 near Stadskanaal; the digital speed signs on the road show 100. Sign B6 and shark's-teeth are present at your entry. A truck is already on the roundabout. What applies?
I have priority, because whoever comes from the right goes first
The truck on the roundabout has priority
I have priority, because I saw the roundabout coming first
When in doubt you may enter as long as the road looks empty
Explanation
False — Who 'sees it first' is not a rule — sign B6 settles this: the truck on the roundabout goes first (Book p.82).