Assertion : The amount of BOD in the water is a measure of the amount of organic material in the water .
Reason : Clear water has BOD less than 5 ppm whereas highly polluted water can have BOD value of 17 ppm or more .

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the c orrect explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

**Step-by-Step Solution:**

1. **Understanding BOD**: BOD stands for Biological Oxygen Demand. It is a measure of the amount of oxygen that microorganisms will consume while decomposing organic matter in water. Thus, it indicates the level of organic pollution in the water.

2. **Assertion Analysis**: The assertion states that the amount of BOD in water is a measure of the amount of organic material in the water. This is true because higher BOD values indicate a higher concentration of organic material, which requires more oxygen for decomposition.

3. **Reason Analysis**: The reason provided states that clear water has a BOD of less than 5 ppm (parts per million), while highly polluted water can have a BOD value of 17 ppm or more. This is also true; clear water typically has low BOD, indicating low organic pollution, whereas higher BOD values signify more organic waste and pollution.

4. **Conclusion**: Since both the assertion and the reason are true, and the reason accurately explains the assertion, we can conclude that both statements are correct and related.

5. **Final Answer**: Therefore, the correct option is that both the assertion and reason are true, and the reason correctly explains the assertion.

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