What should a driver do when experiencing brake failure?

When a driver experiences brake failure, the recommended course of action is to pump the brakes and shift to a lower gear while steering to a safe area. This is correct because pumping the brakes can help regain some hydraulic pressure in the brake system, which might allow for limited braking. Shifting to a lower gear slows the vehicle by using the engine's resistance, assisting in controlling the speed of the vehicle. Steering to a safe area is crucial to prevent accidents and ensure the driver's safety.

In contrast, pulling the handbrake immediately can lead to a loss of control, especially if the vehicle is traveling at a high speed, as it may cause the rear wheels to lock up. Turning off the engine can also be detrimental, as it disables power steering and might make it more challenging to control the vehicle. Using emergency hazards while continuing to drive does not address the immediate need to slow down or stop the vehicle safely, which is the primary concern during brake failure. The combination of these actions in option B prioritizes safety and vehicle control in a critical situation.