When should you pump the brakes on a bus with ABS?

The correct answer is that you should never pump the brakes on a bus equipped with Anti-lock Braking System (ABS). ABS is designed to prevent the wheels from locking up during hard braking, allowing the driver to maintain steering control. When a driver pumps the brakes, it disrupts the effectiveness of the ABS system. Instead, the proper technique when braking with an ABS-equipped vehicle is to apply steady pressure to the brakes and allow the system to manage the brake force appropriately.

It's important to understand that the other choices suggest actions that would either be ineffective or counterproductive when managing a vehicle with ABS. For instance, pumping the brakes on slippery roads might seem logical, but in an ABS-equipped bus, it can negate the benefits of the system's design. Similarly, using pumping brakes in emergency situations or whenever feeling a loss of control would prevent the ABS from functioning effectively, thus compromising safety and control. Understanding the operation of ABS is crucial for safe driving practices in vehicles such as buses which transport passengers.