What should a driver do before starting down a hill?

Answer: C — Shift down to a controllable speed

Before starting down a hill, a driver should shift down to a controllable speed. This action helps to manage the vehicle's speed through the descent. When driving downhill, gravity causes the vehicle to accelerate, and downshifting to a lower gear allows the engine to help control this speed through engine braking. This method enhances the driver's ability to maintain control of the vehicle, reduces reliance on the brakes, and minimizes the risk of brake overheating or failure due to excessive use. Choosing a higher gear may cause the vehicle to gain speed too quickly, making it more difficult to maintain control. Speeding up and then braking is risky, as it creates the danger of losing control due to excess speed before engaging the brakes. Ignoring the gear can lead to an uncontrolled descent, which could result in a hazardous situation for both the driver and others on the road. Shifting down ensures that the vehicle operates safely and effectively when navigating downhill.