Which of the following systems should be included in a pre-trip inspection?

Windshield wipers are a critical component of vehicle safety and visibility, particularly in adverse weather conditions. During a pre-trip inspection, it's essential to ensure that the wipers are functioning correctly. This includes checking the wipers for wear and tear, making sure they clear the windshield effectively, and ensuring that the washer fluid system is operational. Clear visibility through the windshield is vital for safe driving, and ineffective wipers can significantly increase the risk of accidents in rainy or snowy conditions.

While the other systems mentioned may be important for the overall functionality of the vehicle, they do not directly impact immediate safety and visibility in the same manner. The primary focus of a pre-trip inspection is to identify any potential safety hazards that could affect driving performance.