B) Hold a public meeting to talk about ways to save water
The first choice is irrational. What will be the result of this? No one would imprison a person for using too much water, and the citizens would only become angry and stage a revolt against such strict laws.
The second choice is a good way to get everyone involved and thinking. 2 minds work better than 1. This way, we can introduce more ideas and get everyone on board and aware of the plan.
The third option is pretty useless. If there is a drought in one area, there can't be that much water in neighboring areas. The neighboring areas will probably need the water. Also, this will make the citizens more inclined to use water knowing that they have a surplus already. The citizens will not know that they need to preserve water.
Lastly, the last option is impractical. We do not know everyone's schedule or routine. When we use our water might not be when others use their water. Water is greatly used during the day! What can we wash our hands with? What can we drink? What flushes our toilets?
Hope this helps!