When a fast-moving vehicle is suddenly stopped by applying brakes, the force that causes deceleration is exerted by the brake.
Because action and reaction pair are never equal
The force exerted by brake is an internal force for the car. Internal forces can not cause deceleration. The brake's function is just to stop the rotation of the wheels. Once the rotation of the wheels is stopped, the wheels start to slip on the road. The frictional force opposes this slipping and causes deceleration. Hence, the above statement is false.