Answer: B. Avoid water pollution.
Natural resources on earth are of two types called as renewable resources and non-renewable resources. The renewable resources are those which can be replenished after a single use whereas the non renewable resources are those which cannot be used again once used. Renewable resources includes water, and wind. Non renewable resources includes fossil fuels, and minerals.
Although water is a renewable resource but the availability of water for the present and future generation of human population is dependent upon how it is used, protected against contamination. Avoid water pollution is the correct option because if water is kept free from contamination it will remain available for present and future population use. Even small amount of contaminants such as household waste, chemical fertilizers, pesticides, and other wastes can contaminate large amount of water reservoir.
