What must an inspector check regarding a vehicle's lighting system?

The requirement for an inspector to check the functionality of all required lights, including headlights, taillights, brake lights, and turn signals, is essential for several reasons. It ensures that the vehicle meets safety standards as outlined by state regulations. Properly functioning lights are crucial for visibility and communication with other drivers on the road. Headlights allow the driver to see at night or in low-light conditions, while taillights and brake lights signal the vehicle's presence and intentions to others, thereby preventing accidents.

Turn signals are particularly important for safe lane changes and turns, as they inform other road users of the driver's actions. By inspecting all these lights, the inspector verifies that the vehicle adheres to safety protocols, enhancing road safety for everyone.

Other options focus on a limited scope, such as only checking a subset of the lights or specific types of lights, which would not provide a comprehensive assessment of the vehicle's lighting system. Ensuring the entire lighting system functions correctly is critical in maintaining overall vehicle safety and compliance with inspection standards.