What must a pedestrian do if, when about to cross a road, they encounter an officer in front of them with their arm raised vertically?

What must a pedestrian do if, when about to cross a road, they encounter an officer in front of them with their arm raised vertically?
A)Stop.Correct
B)Cross. Officers' signals only apply to drivers of vehicles.
C)Stop, except if a traffic light gives them right of way, in which case they must cross.
Arm raised vertically: Requires all road users approaching the officer to stop, except for drivers who cannot do so safely.
The stop must be made before the nearest stop line or, failing that, immediately before the officer.
At an intersection, the stop must be made before entering it. After this signal, the officer may indicate, where appropriate, the place where the stop must be made.