In the daytime, a bus carrying a group of children has its low beam headlights switched on so that it is noticeable. The emergency light signal is switched on only when children are boarding and alighting.
To make the vehicle more visible during daylight hours, buses carrying organized groups of children must have their low beam headlights on (clause 133). This helps other road users notice the vehicle from a distance.
Option 1. The high beam is not meant for marking a vehicle in the daytime and can needlessly blind others.
Option 3. The emergency light signal is required only when children are boarding or alighting, not all the time while driving.
Option 4. The interior lighting is for use inside and does not help other drivers notice the bus from outside.