What should be done if the vehicle loses its brakes while driving downhill?

Answer: B — Shift to a lower gear and look for a safe area to pull over

When a vehicle loses its brakes while driving downhill, the appropriate action is to shift to a lower gear and look for a safe area to pull over. This technique is essential because downshifting helps to slow the vehicle through engine braking, which can reduce speed and help maintain control over the vehicle. It is critical to find a safe area to pull over as quickly as possible, allowing for a more controlled stop rather than an abrupt and potentially hazardous maneuver. Accelerating to gain control is not advisable, as increasing speed will worsen the loss of control and could lead to an accident. Immediately pulling off the road without assessing the surroundings can lead to unsafe situations, such as crashing into obstacles or endangering other road users. Using only the parking brake can be dangerous, as it may lock up the wheels and cause the vehicle to skid or become uncontrollable, especially on a downhill slope. Therefore, shifting to a lower gear and seeking a safe location is the most effective and responsible response in this emergency situation.