Smog is common pollutant in places having:

Options

A. high altitudes
B. high temperature
C. high concentration of `SO_(2)` in air
D. high concentration of `NH_(3)` in air

Answer

**Step-by-Step Solution:**

1. **Understanding Smog**: Smog is a type of air pollution that is a mixture of smoke and fog. It can be categorized into two main types: photochemical smog and classical smog.

2. **Types of Smog**:
- **Photochemical Smog**: This type occurs in warm and dry climates. It is formed when ultraviolet (UV) radiation from the sun reacts with pollutants such as nitrogen oxides and hydrocarbons. This reaction leads to the formation of ozone at ground level, which is harmful to health.
- **Classical Smog**: This type occurs in humid climates and is primarily formed from sulfur dioxide (SO2) and particulate matter. It is more common in industrial areas where coal burning is prevalent.

3. **Conditions for Smog Formation**:
- **Photochemical Smog**: Requires warm and dry conditions along with the presence of UV light and pollutants like nitrogen oxides and hydrocarbons.
- **Classical Smog**: Requires humid conditions and is associated with high levels of sulfur dioxide and particulate matter.

4. **Health Effects of Smog**: Both types of smog can lead to serious health issues, including respiratory problems, irritation of the eyes, nose, and throat, chest pain, and can trigger asthma attacks.

5. **Identifying the Correct Answer**: The question asks where smog is a common pollutant. Based on the types of smog:
- Photochemical smog is common in warm, dry climates.
- Classical smog is common in humid climates with high concentrations of sulfur dioxide.

6. **Conclusion**: Therefore, smog is a common pollutant in places with high concentrations of sulfur dioxide, particularly in humid climates.

**Final Answer**: Smog is a common pollutant in places having high concentrations of sulfur dioxide (SO2).

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