Given below are two statements, one labelled as Assertion A and the other as Reason R. In the light of the above statements, choose the correct answer from the options given below.

Assertion (A):Oxygen-demanding wastes are substances that oxidize in the receiving body of water.

Reason (R):As bacteria decompose these wastes, they release oxygen in the water.

ABoth A and R are correct and R is the correct explanation of A

BBoth A and R are correct but R is not the correct explanation of A

CA is correct but R is not correct ✓ Correct

DA is not correct but R is correct

Correct answer: (C) A is correct but R is not correct

Explanation

Oxygen-demanding wastes are substances that oxidise in the receiving water body, so Assertion A is correct.

They include biodegradable organic matter from sewage and industry.

The Reason is not correct, because decomposing bacteria consume oxygen rather than release it.

This uptake lowers the dissolved oxygen available to aquatic life.

The amount consumed is measured as biochemical oxygen demand.

A high demand can leave water bodies oxygen-starved and unable to support fish.

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