using sprinklers for fewer hours each week washing vehicles in the middle of the day spraying water to clean oil from parking lots letting faucets run while brushing teeth
I gave my students this multiple choice question: Many people get fresh water from wells that reach water stored underground. When there is little rain, the water can begin to run out. Which step is best to make the water last longer?

Only one answer is correct among these 4 choices:
- using sprinklers for fewer hours each week
- washing vehicles in the middle of the day
- spraying water to clean oil from parking lots
- letting faucets run while brushing teeth

Could you tell me which one is correct?

using sprinklers for fewer hours each week