one safe way to test whether a braking problem is at the front or rear brakes is to drive at a low speed…

one safe way to test whether a braking problem is at the front or rear brakes is to drive at a low speed and:\n\na. lightly apply the service brakes.\n\nb. lightly apply the parking brake.\n\nc. repeatedly tap the service brakes.\n\nd. pull hard on the parking brake lever.
Answer
Brief Explanations:
Repeatedly tapping the service brakes at low - speed can help identify if the braking problem is in the front or rear brakes. Lightly applying the service brakes may not clearly show the problem. Applying the parking brake or pulling hard on the parking brake lever is not a safe or proper way to test front - rear brake issues as it can cause skidding or other unsafe conditions at low speeds.
Answer:
C. Repeatedly tap the service brakes.