Final answer:
To prevent brakes from locking if a vehicle does not have ABS, it's important to use the correct technique known as threshold braking. This involves pushing the brakes hard, releasing slightly if a wheel locks, and repeating. Pumping the brakes quickly and gently pushing on the pedal are not effective methods.
Step-by-step explanation:
When braking in a vehicle that does not have ABS (Anti-lock Braking System), it's important to use the correct technique to prevent the brakes from locking. Option C is the correct answer: press the brakes hard, release slightly if a wheel locks, and repeat. This technique, known as threshold braking, allows the driver to maintain control over the vehicle and prevent skidding. When a wheel locks up, it loses traction with the road, resulting in the vehicle sliding instead of stopping.
Pumping the brakes hard and fast, as mentioned in option B, can actually worsen the situation by causing a loss of control. Option A, only pushing gently on the brake pedal, may not provide enough stopping power and could lead to longer stopping distances.
By applying firm pressure on the brake pedal and releasing slightly if a wheel locks, the driver can maintain maximum braking force while allowing the tires to regain traction and prevent the brakes from locking up.