Which of the following items must be in proper working condition on a vehicle transporting ammunition?

The requirement for brakes and tires to be in proper working condition on a vehicle transporting ammunition is critical for ensuring safe and effective transport. Brakes are essential for controlling the vehicle and ensuring it can stop promptly, especially when navigating through areas that require heightened attention due to the presence of hazardous materials like ammunition. Similarly, properly functioning tires are fundamental for maintaining traction and stability during transport, which is particularly important when transporting explosive materials that could become dangerous if the vehicle were to lose control.

Ensuring that these components are in optimal condition minimizes the risk of accidents that could lead to catastrophic consequences, such as fires or explosions. This highlights the importance of conducting thorough inspections of the vehicle to verify that all safety-critical components are functioning correctly before transporting ammunition.