What is the function of an anti-lock braking system (ABS)?

The function of an anti-lock braking system (ABS) is to prevent wheel lock-up during hard braking, which significantly improves control of the vehicle. When a driver applies the brakes forcefully, especially in slippery conditions, there's a risk that the wheels may stop turning—this is known as wheel lock-up. When all wheels lock, the vehicle can skid, making it difficult for the driver to steer.

ABS uses sensors to monitor the speed of each wheel and, if it detects that any wheel is beginning to lock, it reduces brake pressure on that wheel. This allows the wheel to keep turning, providing the driver with better steering control and helping to maintain traction. The end result is a safer stop and a lower likelihood of losing control of the vehicle.

The other options do not relate to the primary function of ABS. For example, increasing fuel efficiency, lowering the center of gravity, and enhancing speed during acceleration do not pertain to braking or maintaining control of a vehicle during a stop, which is the core purpose of an anti-lock braking system.