Brush for three minutes. Turn the water off before brushing. Rinse mouth with the running water. Use less toothpaste on the toothbrush.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A student provides the following directions for brushing teeth: • Turn on the water. • Fill the glass with water and leave the water running. • Put toothpaste on the toothbrush. • Brush for two minutes. • Rinse mouth with the water from the glass. • Rinse the toothbrush with the running water. • Turn off the water. Which change in these directions would conserve the most water?
Possibilities:
- Brush for three minutes.
- Turn the water off before brushing.
- Rinse mouth with the running water.
- Use less toothpaste on the toothbrush.

Turn the water off before brushing.