Assertion: Water pollutants are measured by BOD.
Reasoning:: If BOD is more, the water is polluted.
Reasoning:: If BOD is more, the water is polluted.
Answer & explanation
Correct answer: option 1
Assertion is correct as, water pollutants are commonly measured by their main common denominator, called as BOD (Biochemical Oxygen Demand) which is defined as amount of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.
Reason is correct and correct explanation of assertion as, if water is polluted, it will consume more oxygen, thereby enhancing the BOD of water.