Which of the following is a biodegradable pollutant?

Options

A. Sewage
B. Plastic
C. Polythene
D. DDT

Answer

### Step-by-Step Solution:

1. **Understand the Concept of Biodegradable Pollutants**:
- Biodegradable pollutants are substances that can be broken down into simpler, harmless substances by the action of microorganisms such as bacteria and fungi over time.

2. **Identify Examples of Biodegradable Pollutants**:
- Common examples include domestic waste, sewage, urine, paper, and cattle dung. These materials can decompose naturally.

3. **Differentiate Between Biodegradable and Non-Biodegradable Pollutants**:
- Non-biodegradable pollutants are substances that cannot be broken down by natural processes. Examples include plastics, polythene, DDT (Dichlorodiphenyl trichloroethane), and mercury.

4. **Analyze the Given Options**:
- The options provided are: sewage, plastic, polythene, and DDT.
- From the definitions, we can categorize each:
- **Sewage**: Wastewater from domestic sources that can be decomposed by microorganisms.
- **Plastic**: A synthetic material that does not decompose easily.
- **Polythene**: A type of plastic that is also non-biodegradable.
- **DDT**: A chemical pesticide that is harmful and does not break down easily.

5. **Conclude the Answer**:
- Based on the analysis, the only biodegradable pollutant among the options is **sewage**.

### Final Answer:
- **Sewage is a biodegradable pollutant.**

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