How can drivers ensure they have sufficient air pressure before operating a vehicle?

Answer: B — By monitoring the air pressure gauge

Monitoring the air pressure gauge is the most effective way for drivers to ensure they have sufficient air pressure before operating a vehicle. The air pressure gauge provides a direct reading of the current air pressure in the brake system, allowing the driver to verify that it is within the safe operating range necessary for effective braking. Checks like inspecting the brake fluid level, visually inspecting the brakes, or listening for air leaks do not provide specific information about the air pressure in the brake system. While these actions can be useful for general maintenance or troubleshooting, they do not replace the need to confirm that the air pressure is adequate for safe operation. The air pressure gauge is essential for drivers to assess the status of the air brake system accurately.