Answer:
c. threshold
Explanation:
There is point of braking beyond which the car's wheel will lock and start slipping. In order to make sure that the car's wheels do not lock but at the same time the maximum braking force is applied threshold braking is used.
In threshold braking the brake is pressed just before the point where the car starts slipping. This is the maximum braking force that can be applied without letting the car's wheel lock.
Hence, the statement is referring to threshold braking.
