Goal 1.4 requires using the gear ratio according to the vehicle's load and the road profile. Which choice matches that rule?

1. Use the same high gear empty or laden, uphill or down, to save fuel
2. Leave an automatic gearbox in a sport mode that ignores load
3. Neutral on every downhill as soon as the vehicle is laden
4. Select a lower ratio when the vehicle is heavy or the road climbs or falls steeply, so the engine and brakes stay in their useful range