What should a driver do if the air pressure gauge fluctuates excessively?

Answer: C — Have the system inspected by a professional

When the air pressure gauge fluctuates excessively, it indicates a potential issue with the air brake system that could compromise the safety and performance of the vehicle. It is crucial for a driver to have the system inspected by a professional to ensure that any underlying problems are properly diagnosed and repaired. A fluctuation in air pressure can be caused by a number of factors, such as leaks in the system, malfunctioning components, or improper air supply, all of which could lead to brake failure if not addressed. Monitoring the gauge for an extended period or checking the brake system themselves may not adequately resolve the issue, as these approaches lack the necessary expertise and tools to accurately assess the situation. Ignoring the fluctuations poses a significant safety risk, as it could result in brake failure while on the road. Therefore, seeking a professional inspection is the safest and most responsible course of action when faced with excessive fluctuations in the air pressure gauge.