What is the primary function of stab braking?

Answer: B — To apply the brakes and release them after the wheels lock

Stab braking is a specific technique used primarily in emergency situations, particularly when driving large vehicles such as trucks and buses. The main purpose of stab braking is to prevent the wheels from locking up while managing a quick stop. In this method, the driver applies the brakes as hard as possible until the wheels begin to lock. Once the wheels are locked, the driver must release the brakes, allowing the wheels to start rolling again before reapplying the brakes firmly. This technique helps to maintain steering control, preventing skids and allowing the driver to maneuver the vehicle effectively while decelerating. The other options presented refer to different braking techniques that do not align with the principles of stab braking. Maintaining a consistent speed does not apply to stab braking since the focus is on a rapid deceleration. Gradually decelerating a vehicle is more associated with gentle braking methods that don't involve locking the tires. Finally, while stab braking can help manage stopping in an emergency, its primary function is to handle the brakes correctly during a sudden stop, not necessarily to provide a smoother stopping experience.