The correct option is C Drinking less amount of water
Water conservation is the process of preventing wastage of water and using it wisely.
Water conservation can be done by:
1) Repairing leaking pipes and taps.
2) Collecting rainwater and reusing it for domestic purposes.
3) Taking short showers.
An average adult human being needs atleast two litres of water daily, to stay healthy. So, drinking less amount of water is not an effective method to save water.