In what situation should lower gears be used in a vehicle?

Answer: B — When going downhill or starting from a stop

Lower gears are essential for certain driving conditions, particularly when going downhill or starting from a stop. When navigating downhill, using lower gears helps in controlling the vehicle's speed, allowing the engine to assist in braking by increasing engine RPMs and generating more resistance to motion. This prevents the vehicle from gaining excessive speed, which is critical for safety. Starting from a stop also benefits from lower gears. They provide more torque, making it easier to accelerate from a complete halt, especially in heavier vehicles or when towing. This can significantly help avoid stalling and enables a smoother transition from stationary to moving. In contrast, using lower gears during high-speed turns or when driving at high speeds could lead to a loss of control and increased wear on the engine. On straight roads, lower gears are typically unnecessary and can limit the vehicle’s performance.