Biochemical Oxygen Demand, (BOD) is a measure of organic material present in water. BOD value less than 5 ppm indicates a water sample to be __________.
(i) rich in dissolved oxygen.
(ii) poor in dissolved oxygen.
(iii) highly polluted.
(iv) not suitable for aquatic life.
The answer is the option (i) Rich in dissolved oxygen
Explanation: BOD refers to the amount of oxygen consumed by microorganism in water. It the value of BOD is less than 5 ppm, then the water is considered to be pure or rich in dissolved oxygen.