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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Polluted water may have a value of BOD of the order of 17 ppm. Reason R: BOD is a measure of oxygen required to oxidise both the bio-degradable and non-bio-degradable organic material in water. In the light of the above statements, choose the most appropriate answer from the options given below. (1) Both A and R are correct and R is the correct explanation of A. (2) Both A and R are correct but R is NOT the correct explanation of A. (3) A is correct but R is not correct. (4) A is not correct but R is correct.

1. Both A and R are correct and R is the correct explanation of A.
2. Both A and R are correct but R is NOT the correct explanation of A.
3. A is correct but R is not correct.
4. A is not correct but R is correct.

Correct answer: A is correct but R is not correct.

Solution

The assertion is accurate as polluted water can have a BOD value around 17 ppm, indicating a significant level of organic pollution. However, the reason provided is incorrect because BOD specifically measures the oxygen needed to decompose biodegradable organic matter, not non-biodegradable materials.

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