Answer:
B (Water pollution)
Explanation:
Water pollution is the release of harmful substances -often chemicals and microorganisms- into a water body e.g. stream, river, ocean, lake etc. degrading the quality of the waterbody and rendering it toxic to humans or the environment.
Water is regarded a universal solvent i.e. it has the ability to dissolve more substances than any other liquid on earth. This is the reason why water is vulnerable to pollution or easily polluted as toxic substances readily dissolve into and mix with them, causing water pollution.
Water bodies can be polluted by a variety of substances causing contamination due to pathogenic microorganisms, domestic wastes (sewage and refuse), insecticides, herbicides, food processing wastes, volatile organic compounds, heavy metals, oil spillage from industries, chemical wastes from farms etc. These substances are called POLLUTANTS.