Concept:A zebra crossing gives priority to pedestrians who are already on it.
Explanation:The diagram shows a zebra crossing with pedestrians on the striped area.
Drivers must stop when pedestrians have stepped onto the crossing.
This is a road safety rule, not because it is an emergency crossing line.
The traffic warden is not shown instructing vehicles to stop.
The traffic light is not shown as green for vehicles.
Therefore, the vehicles stop mainly because pedestrians are already on the crossing line.
Answer:B. the pedestrians have already stepped on the line.
