The water quality of a pond was analysed and its BOD was found to be 4. The pond has :

Options

A. Water has high amount of fluoride compounds
B. Highly polluted water
C. Very clean water
D. Slightly polluted water

Answer

To solve the question regarding the BOD (Biological Oxygen Demand) of the pond water, we will analyze the given BOD value and determine the quality of the water based on standard classifications.

### Step-by-Step Solution:

1. **Understand BOD**:
- Biological Oxygen Demand (BOD) is a measure of the amount of dissolved oxygen that aerobic microorganisms will consume while decomposing organic matter in water. It is an important indicator of water quality.

2. **Identify BOD Value**:
- The problem states that the BOD of the pond water is 4.

3. **Classify Water Quality Based on BOD**:
- Generally, BOD values are interpreted as follows:
- BOD < 5: Very clean water
- BOD between 5 and 15: Slightly polluted water
- BOD > 15: Highly polluted water

4. **Determine the Quality of the Pond Water**:
- Since the BOD value of the pond is 4, which is less than 5, we can classify the water quality.

5. **Conclusion**:
- The pond has very clean water.

### Final Answer:
The pond has very clean water.

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