which is not a pollutant from exhaust of motor vehicle ?

Options

A. Hydrocarbons gas
B. Fly ash
C. `SO_(2)`
D. CO.

Answer

To solve the question "Which is not a pollutant from the exhaust of a motor vehicle?" we will analyze the options provided and identify the correct answer step by step.

### Step 1: Understand the question
The question asks us to identify which of the given options is NOT a pollutant emitted from the exhaust of a motor vehicle.

### Step 2: Review the options
The options given are:
1. Hydrocarbon gas
2. Fly ash
3. Sulphur dioxide
4. Carbon monoxide

### Step 3: Analyze each option
- **Hydrocarbon gas**: This is a known pollutant from vehicle exhaust. Hydrocarbons are emitted during the combustion of fuel in engines.

- **Fly ash**: This is primarily a byproduct of burning fossil fuels, especially coal, in power plants and industrial processes. It is not emitted from motor vehicles.

- **Sulphur dioxide**: This gas is produced from the combustion of fossil fuels and is also a pollutant found in vehicle exhaust, especially from diesel engines.

- **Carbon monoxide**: This is another common pollutant from motor vehicle exhaust, produced during incomplete combustion of carbon-containing fuels.

### Step 4: Identify the correct answer
From the analysis, we see that:
- Hydrocarbon gas, sulphur dioxide, and carbon monoxide are all pollutants emitted from motor vehicles.
- Fly ash is not emitted from motor vehicles; it is a byproduct of burning coal and other fossil fuels in power generation.

Therefore, the answer to the question is **Fly ash**.

### Final Answer
**Fly ash** is not a pollutant from the exhaust of a motor vehicle.

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