The most suitable option would be C take baths instead of showers.
When doing this, you are using just an amount of water and you avoid water to keep on running. The main idea should be to reduce water usage so you need to pay attention not only when you take a bath but also when you brush your teeth. leave the water running while doing anything is one of the ways in which water is highly wasted.
You only use a certain amount of water in baths, in showers the water keeps coming.