Question:
Assertion (A): If BOD level of water in a reservoir is less than 5 ppm it is
highly polluted.
Reason (R): High biological oxygen demand means a low activity of bacteria
in water.
(i) Both A and R are correct and R is the correct explanation of A.
(ii) Both A and R are correct but R is not the correct explanation of A.
(iii) Both A and R are not correct.
(iv) A is not correct but R is correct.
Solution:
Option (iii) is the answer.