How can a defective brake line be identified?

Answer: B — By visual inspection for cracks, bends, or leaks

Identifying a defective brake line primarily involves visual inspection for signs of physical damage. This includes looking for cracks, bends, or any leaks in the brake line. A brake line that has been compromised can lead to a loss of hydraulic pressure, which is crucial for effective braking. Observing the brake line allows technicians to spot issues that could significantly affect the brake system's performance and safety. While checking brake light functionality, measuring brake pad thickness, and testing air pressure in the system are important maintenance tasks, they do not directly indicate the condition of the brake lines themselves. The brake lights may function properly even if the brake lines are damaged, and failures in pads or air pressure do not reflect the integrity of the brake lines. Visual inspection remains the most straightforward and effective method to ascertain the condition of the brake lines.