To determine the order of activities from greatest to least impact in reducing fossil fuel consumption, we should consider the energy efficiency and fossil fuel dependency of each option:
- Walk to work - This has the greatest impact as it eliminates fossil fuel consumption entirely.
- Carpool to work - This reduces the number of vehicles on the road and lowers fossil fuel consumption compared to driving alone.
- Drive an electric car to work - While electric cars are more environmentally friendly, the source of electricity can still involve fossil fuels, though it's generally more efficient.
- Drive alone to work - This has the least impact since it results in the highest fossil fuel use per person.
Based on this reasoning, the order that correctly reflects the greatest to least impact would be:
Walk to work, carpool to work, drive an electric car to work.
However, since that option is not given, the best response out of the provided options would be:
Walk to work, carpool to work, drive alone to work.