Choose the correct words to fill in the blanks .
Pollutant is defined as , a substance or an agent which causes pollution. `……` and `…..` are chemical pollutants . Pollutants can be `…….` which rapidly break down by `…..` process .

Options

A. Heavy metal-DDT-degradable -natural
B. Particulates- heavy metal-non-degradable-artificial
C. Non-degradable-petroleum-degradable-artificial
D. Microorganisms-natural gas-nondegradable-natural

Answer

To solve the question, we need to fill in the blanks with appropriate words related to pollutants. Let's break down the question step by step.

### Step-by-Step Solution:

1. **Understanding the Definition**:
- The first part of the question defines a pollutant as a substance or an agent that causes pollution. This is straightforward and sets the context for what we are discussing.

2. **Identifying Chemical Pollutants**:
- The question asks for two examples of chemical pollutants. From the video transcript, we learn that heavy metals and DDT (Dichloro-Diphenyl-Trichloroethane) are mentioned as examples of chemical pollutants.
- Therefore, we fill in the first two blanks with:
- **Heavy metals** and **DDT**.

3. **Understanding the Nature of Pollutants**:
- The next part of the question states that pollutants can be something that rapidly breaks down. The transcript mentions that there are pollutants that can be biodegraded, which means they can break down naturally.
- Thus, we fill in the third blank with:
- **Biodegradable**.

4. **Identifying the Process of Breakdown**:
- Finally, the question asks what process allows these pollutants to break down. The transcript indicates that these biodegradable pollutants are broken down by microorganisms through natural processes.
- Therefore, we fill in the last blank with:
- **Natural processes**.

### Final Answer:
Pollutant is defined as a substance or an agent which causes pollution. **Heavy metals** and **DDT** are chemical pollutants. Pollutants can be **biodegradable** which rapidly break down by **natural processes**.