Final answer:
The proper procedure for use of the amber warning light system is to activate the lights before the bus stop and then deactivate them after coming to a complete stop at the bus stop.
Step-by-step explanation:
The proper procedure for use of the amber warning light system is both A and B. A. The amber warning light should be activated 200' before the school bus stop, where NOT exempted. This serves as a signal to other road users that the bus will be stopping soon. B. After coming to a complete stop at the bus stop, the amber lights should be deactivated and the red crossover lights should be activated. This allows for the safe crossing of students in front of the bus.