Arrange the following options in ascending order of their BOD value.
I. Sample of highly polluted pond water.
II. Sample from unpolluted pond water.
III. Distilled water

Options

A. III `to` I `to` II
B. II `to` III `to`
C. III ` to` II `to` I
D. I`to` III`to` II

Answer

To arrange the given options in ascending order of their Biological Oxygen Demand (BOD) values, we need to understand the concept of BOD and how it relates to water pollution.

### Step-by-Step Solution:

1. **Understanding BOD**:
- BOD (Biological Oxygen Demand) measures the amount of oxygen required by microorganisms to decompose organic matter in water.
- A higher BOD indicates a higher level of pollution, as more organic matter requires more oxygen for decomposition.

2. **Analyzing the Options**:
- **I. Sample of highly polluted pond water**: This sample will have a **high BOD** because it contains a lot of organic matter that needs to be decomposed.
- **II. Sample from unpolluted pond water**: This sample will have a **moderate BOD** since it has some organic matter, but much less than the highly polluted sample.
- **III. Distilled water**: This is the purest form of water, free from contaminants and organic matter, thus it has the **lowest BOD** or effectively no BOD.

3. **Arranging in Ascending Order**:
- Based on the analysis, we can arrange the options in ascending order of their BOD values:
- **III. Distilled water** (lowest BOD)
- **II. Sample from unpolluted pond water** (moderate BOD)
- **I. Sample of highly polluted pond water** (highest BOD)

### Final Arrangement:
The ascending order of BOD values is:
**III < II < I**