What component is responsible for reducing pressure in the air brake system during normal braking?

Answer: C — Brake control valve

The brake control valve plays a crucial role in the air brake system by regulating the pressure to the brake chambers during normal braking. When the driver applies the brakes, the valve allows air to flow from the air tanks into the brake chambers, increasing the pressure and engaging the brakes. Conversely, when the brakes are released, the brake control valve reduces the pressure in the system, allowing the brakes to disengage. This pressure modulation is essential for smooth and controlled braking action. In the context of air brake function, other components have distinct roles. The compressor generates air pressure for the system but does not directly control it during braking. Air tanks store compressed air but rely on the brake control valve to manage the flow of air to the brake chambers. Brake chambers convert air pressure into mechanical force to apply the brakes but do not influence the pressure reduction during braking themselves. Thus, the brake control valve is indeed the correct choice as it is directly responsible for managing air pressure in the braking process.