Which light emitted from the rear of a vehicle must be white?

• A. Back-up lamp
• B. Tail lamp
• C. License plate light
• D. Brake light

Answer: (A)

The light emitted from the rear of a vehicle that must be white is the back-up lamp. Back-up lamps are specifically designed to illuminate when a vehicle is in reverse, providing visibility for the driver and signaling to other road users that the vehicle is moving backward. The purpose of these lights is to enhance safety, making it easier for pedestrians and other drivers to see the vehicle as it backs up.

In contrast, tail lamps are required to emit red light, which serves to signal the presence of the vehicle and its braking status to drivers behind it. The license plate light must also emit white light, but it is specifically meant to illuminate the vehicle's license plate rather than function as a general indicator of vehicle movement. Brake lights must also emit red light, signaling when the driver is applying the brakes. Thus, the requirement for back-up lamps to be white is clear and aligns with their specific safety function in vehicular operation.