Sewage containing organic waste should not be disposed in water bodies because it causes major water pollution. Fishes in such a polluted water die because of

Options

A. Large number of mosquitoes
B. Increase in the amount of dissolved oxygen
C. Decrease in the amount of dissolved oxygen in water
D. Clogging of gills by mud

Answer

C

Explanation

Dissolved oxygen is essential for aquatic life. Organic waste is oxidised by microorganisms using dissolved oxygen. Hence, oxygen from water decreases. It is harmful for aquatic life.