Which one of the following gaseous pollutants is carcinogenic?

Options

A. Oxides of sulphur
B. Oxides of nitrogen
C. Arsenic
D. Oxides of carbon

Answer

To determine which gaseous pollutant is carcinogenic from the options given, we can analyze each option step by step.

### Step 1: Identify the options
The options provided are:
A. Oxides of sulfur
B. Oxides of nitrogen
C. Arsenic
D. Oxides of carbon

### Step 2: Understand the nature of each option
- **Oxides of Sulfur (SOx)**: These are primarily sulfur dioxide (SO2) and sulfur trioxide (SO3). While they can cause respiratory issues and contribute to acid rain, they are not classified as carcinogenic.

- **Oxides of Nitrogen (NOx)**: This includes nitrogen dioxide (NO2) and nitric oxide (NO). These gases can lead to respiratory problems and are involved in the formation of smog, but they are not known to be carcinogenic.

- **Arsenic**: Although arsenic is not a gas at room temperature, it can exist in gaseous forms in certain environments. Arsenic is a well-known carcinogen associated with various cancers, particularly skin, bladder, and lung cancers.

- **Oxides of Carbon (COx)**: This includes carbon monoxide (CO) and carbon dioxide (CO2). Carbon monoxide is toxic but not classified as a carcinogen, while carbon dioxide is a natural component of the atmosphere and is not carcinogenic.

### Step 3: Conclusion
Among the options, arsenic is recognized as a carcinogenic substance, making it the correct answer.

### Final Answer
C. Arsenic is the carcinogenic gaseous pollutant.

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