Which of two water sample A & B with BOD of 10ppm and 20 ppm respectively, then mark correct option

Options

A. A is more polluted
B. B is more polluted
C. A and B both are equally polluted
D. A and B both are equally suitable for drinking.

Answer

To determine which of the two water samples A and B is more polluted based on their Biochemical Oxygen Demand (BOD), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding BOD**:
- BOD stands for Biochemical Oxygen Demand. It measures the amount of oxygen that microorganisms will consume while decomposing organic matter in water. Higher BOD values indicate a higher level of organic pollution.

2. **Given Data**:
- Sample A has a BOD of 10 ppm.
- Sample B has a BOD of 20 ppm.

3. **Interpreting BOD Values**:
- A BOD of less than 5 ppm indicates that the water is clean and suitable for drinking.
- A BOD greater than 17 ppm indicates that the water is polluted.

4. **Analyzing Sample A**:
- Sample A (10 ppm) is above the clean water threshold (5 ppm) but below the polluted threshold (17 ppm). Therefore, it is somewhat polluted but not heavily.

5. **Analyzing Sample B**:
- Sample B (20 ppm) exceeds the polluted threshold (17 ppm), indicating that it is heavily polluted.

6. **Conclusion**:
- Since Sample B has a higher BOD (20 ppm) compared to Sample A (10 ppm), we conclude that Sample B is more polluted than Sample A.

7. **Identifying the Correct Option**:
- The options provided include statements about the pollution levels of both samples. The correct option is that Sample B is more polluted than Sample A.

### Final Answer:
- **Option 2**: B is more polluted.