What should be done if the vehicle's brakes feel spongy?

Answer: B — Check for air in the brake lines

If the vehicle's brakes feel spongy, it is crucial to check for air in the brake lines. A spongy feeling typically indicates that there is air trapped within the hydraulic brake system, which can lead to a decrease in braking effectiveness. When air is present in the brake lines, it can compress when the brake pedal is pressed, resulting in a less responsive braking action. This phenomenon occurs because air is compressible, unlike brake fluid, which is not. Bleeding the brakes may be necessary to remove any trapped air and restore the proper hydraulic pressure. Ensuring that the brake lines are free of air is vital for maintaining safe braking performance. While adjusting the brake fluid levels can be important, simply adding more fluid may not solve the issue if air is already present in the system. Checking brake pads for wear is also an important part of brake maintenance but does not directly address the sponginess caused by air in the brake lines. Understanding this will help you identify and resolve braking issues effectively during your pre-trip inspection.