Question

If BOD of river is high, it means that the river is:

• A. not polluted
• B. very much polluted with inorganic chemicals
• C. very much polluted with organic chemicals which are decomposed by micro-organisms
• D. polluted with pesticides

Answer 1

The correct option is C very much polluted with organic chemicals which are decomposed by micro-organisms

BOD (biological oxygen demand) is a measure of the oxygen utilised by microorganisms during oxidation of organic materials.
BOD is directly proportional to the amount of organic waste which is to be broken down.
Hence the correct option is 'c'.