Biochemical Oxygen Demand, (BOD) is a measure of organic material present in water. BOD value less than `5 "ppm"` indicates a water sample to be

Options

A. rich in dissolved oxygen
B. poor in dissolved oxygen
C. highly polluted
D. not suitable for aquatic life

Explanation

**Step-by-Step Solution:**

1. **Understanding BOD**: Biochemical Oxygen Demand (BOD) is a measure of the amount of dissolved oxygen that is required by aerobic bacteria to decompose organic matter in water. It indicates the level of organic pollution in the water.

2. **Interpreting BOD Value**: The question states that the BOD value is less than 5 ppm (parts per million). A low BOD value suggests that there is a minimal amount of organic material present in the water sample.

3. **Implication of Low BOD**: Since the BOD is low (less than 5 ppm), it indicates that there are very few organic compounds in the water. This means that the aerobic bacteria do not require much oxygen to decompose these organic materials.

4. **Dissolved Oxygen Availability**: With fewer organic compounds present, the oxygen that is dissolved in the water is not being consumed by the aerobic bacteria. Therefore, the amount of dissolved oxygen in the water remains high.

5. **Conclusion**: Since the BOD is low and there is a high availability of dissolved oxygen, we can conclude that the water sample is rich in dissolved oxygen.

**Final Answer**: A BOD value of less than 5 ppm indicates that the water sample is rich in dissolved oxygen.

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