Biology · MICROBES IN HUMAN WELFARE

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): During secondary treatment of sewage, a small part of the activated sludge is pumped back into the aeration tank to serve as the inoculum. Reason (R): The remaining major part of the sludge is pumped into anaerobic sludge digesters to produce biogas. In the light of the above statements, choose the correct answer from the options given below:

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
3. Statement (A) is true but (R) is false.
4. Statement (A) is false but (R) is true.