Which of the following is required for passenger cars?

The requirement for passenger cars to have working lights, including two headlights and tail lights, is critical for safe operation. These lights serve several essential purposes: they enhance visibility for the driver, making it easier to see the road and obstacles, and they allow other drivers and pedestrians to see the vehicle, which helps prevent accidents.

In many jurisdictions, having a minimum of two operational headlights and tail lights is mandated by law to ensure that vehicles can be safely driven at night or in low-visibility conditions. The presence of these lights is crucial for signaling other drivers, indicating when the vehicle is turning, stopping, or in motion, and overall contributes to road safety.

Passenger air conditioning, advanced GPS navigation systems, and special highway-only tires, while they may offer comfort and convenience, are not standard legal requirements for passenger cars. Thus, the most critical and legally required feature from the options provided is the working lights, which contribute directly to the safety of both the vehicle occupants and other road users.