Measurement of dissolved oxygen that would be needed by the microorganism to oxidise the compounds is known as

Options

A. Acid rain
B. BOD
C. COD
D. Ozone layer depletion

Answer

To solve the question, "Measurement of dissolved oxygen that would be needed by the microorganisms to oxidise the compounds is known as," we need to identify the correct term that describes this measurement.

### Step-by-Step Solution:

1. **Understanding the Question**: The question is asking for a specific term that refers to the measurement of dissolved oxygen required by microorganisms to decompose organic matter in water.

2. **Identifying Key Terms**: The key terms in the question are "dissolved oxygen," "microorganisms," and "oxidise compounds." This indicates that we are looking for a biological process involving oxygen consumption.

3. **Considering Possible Answers**: The options provided in the context (though not explicitly listed in the question) likely include terms such as BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), acid rain, and ozone layer depletion.

4. **Defining BOD**: BOD stands for Biochemical Oxygen Demand. It is the amount of dissolved oxygen needed by aerobic microorganisms to decompose organic matter in a water sample. This directly relates to the question as it measures the oxygen required for the oxidation of organic compounds by microorganisms.

5. **Defining COD**: COD stands for Chemical Oxygen Demand. It measures the total oxygen required to oxidize both organic and inorganic substances in water. Since the question specifically refers to microorganisms oxidizing compounds, COD is not the correct answer.

6. **Eliminating Other Options**:
- **Acid Rain**: This refers to rain that has been made acidic by pollutants in the atmosphere, not related to the measurement of oxygen.
- **Ozone Layer Depletion**: This refers to the reduction of ozone in the atmosphere due to pollutants, which is also unrelated to the measurement of dissolved oxygen.

7. **Conclusion**: Based on the definitions and the context of the question, the correct answer is **BOD (Biochemical Oxygen Demand)**.

### Final Answer:
The measurement of dissolved oxygen that would be needed by the microorganisms to oxidise the compounds is known as **Biochemical Oxygen Demand (BOD)**.

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