Final answer:
When going down a steep hill, you should shift into a lower gear.
Step-by-step explanation:
When going down a steep hill, you should shift into a lower gear (option B).
By shifting into a lower gear, you can take advantage of engine braking, which uses the resistance of the engine to slow down the vehicle. This helps to maintain control and prevent the brakes from overheating.
For example, if you're driving a manual transmission car, you would shift from a higher gear (such as 4th or 5th) to a lower gear (such as 2nd or 3rd) when going downhill.