What light condition can lead to an inspection failure?

The condition that can lead to an inspection failure is when any light on the dashboard remains illuminated after the vehicle is started. This is significant because dashboard warning lights provide crucial notifications about potential issues with the vehicle’s systems, such as the engine, brakes, or other safety features. If a warning light is on, it indicates that there may be a malfunction that could compromise the vehicle's safe operation, which is why it is a critical aspect of the inspection process.

In contrast, the other conditions do not reflect the same level of concern for safety. Having all lights out does not accurately represent a common scenario or requirement for vehicle operation, as certain lights must function. Only ensuring headlights work does not cover the comprehensive functionality needed from all vehicle lights, including turn signals and tail lights. Although checking brake lights periodically is important for maintenance, it doesn't directly correlate to the conditions required for passing a state inspection, which mandates that warning lights are not illuminated during a thorough inspection.