(iii) Both A and R are not correct.
Explanation:BOD value is more than 17 ppm for the more polluted water bodies whereas it is less than 5 ppm for the clean water bodies. Biological Oxygen Demand is defined as the amount of oxygen required by the bacteria to break down the organic matter into simpler compounds. Further, the BOD value is directly related with the amount of organic matter present in the water sample which is available for the bacteria to break upon. Therefore, high biological oxygen demand value means high activity of bacteria in water.
Rate this question :