Which indicator lights are required to function for Class A vehicles?

The correct answer highlights the essential indicator lights that are critical for the safety and operation of Class A vehicles. ABS (Anti-lock Braking System), TPMS (Tire Pressure Monitoring System), Airbag, and BRAKE lights are integral to the vehicle's safety systems.

The ABS light indicates if there is an issue with the anti-lock braking system, which helps prevent wheel lockup during braking, thereby maintaining vehicle control. The TPMS light indicates if tire pressure is too low, which is crucial for safe driving and can prevent blowouts. The Airbag light shows the readiness of the airbag system, indicating whether it will deploy properly in the event of a collision. Lastly, the BRAKE light is important as it alerts the driver to issues with the brake system that could impair stopping ability.

These lights are required for vehicles to ensure maximum safety and compliance with regulations. Other options may include useful indicator lights, but they do not encompass all the critical systems necessary for a Class A vehicle's safe operation as specified in inspection standards.