Why is it important to be in the proper gear before descending a hill?

Answer: B — You may not be able to shift down

Being in the proper gear before descending a hill is crucial for maintaining control of the vehicle. When a commercial vehicle, such as a truck, starts descending a hill, its weight can cause it to accelerate due to gravity. If the vehicle is not in the correct lower gear before starting the descent, it may become difficult or impossible to downshift later, especially when more braking power is needed to control the speed on the incline. Selecting a lower gear before descending helps to utilize engine braking, which provides additional control and minimizes the reliance on brakes alone. This is important because relying solely on the brakes can lead to overheating and reduced braking efficiency. Therefore, ensuring that you are in the right gear ahead of time is vital for maintaining safe speed and control, preventing potential accidents or loss of vehicle control while navigating downhill.