Which light systems must be inspected during the auto inspection?

The correct choice emphasizes the comprehensive nature of the light systems that are crucial for vehicle safety and compliance with inspection regulations. During an auto inspection, it is essential to assess headlights, brake lights, turn signals, and parking lights, as all these systems play pivotal roles in ensuring that a vehicle is visible and can signal its intentions to other road users.

Headlights are necessary for visibility during nighttime driving or adverse weather conditions. Brake lights are critical for alerting other drivers when a vehicle is slowing down or stopping, which is vital for avoiding collisions. Turn signals are integral for communicating lane changes or turns, enhancing overall road safety. Additionally, parking lights provide visibility when a vehicle is parked on or near the roadway, helping to prevent accidents.

In contrast, the other options present a limited scope of inspection. Only inspecting headlights and tail lights would overlook other vital lighting functions. Focusing solely on brake lights and hazard lights excludes important signals like turn indicators and parking lights. Additionally, restricting inspection to only high-beam headlights would not ensure the vehicle’s lighting system is fully operational for safe driving.

Overall, the comprehensive inspection of all specified light systems ensures that the vehicle is safe for operation and compliant with Pennsylvania's regulations.