The major source of pollution upto `80%` of total air pollution in metropolitan cities is

Options

A. automobiles (Traffic) /Transportation
B. coal based industries
C. pesticides
D. radioactivity and noise

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the major source of air pollution that contributes up to 80% of total air pollution in metropolitan cities.

2. **Identifying Possible Sources**: The options provided are:
- A) Automobile and traffic transportation
- B) Coal-based industries
- C) Pesticides
- D) Radioactivity and noise

3. **Analyzing Each Option**:
- **Option A (Automobile and traffic transportation)**: This is a significant source of air pollution in metropolitan areas due to the high volume of vehicles. They emit harmful pollutants such as nitrogen oxides, carbon monoxide, carbon dioxide, sulfur oxides, and hydrocarbons.
- **Option B (Coal-based industries)**: While these industries do contribute to air pollution, their impact is generally less than that of automobiles in urban settings.
- **Option C (Pesticides)**: Pesticides contribute to environmental pollution but are not a major source of air pollution in metropolitan cities.
- **Option D (Radioactivity and noise)**: These are not primary contributors to air pollution.

4. **Conclusion**: Based on the analysis, it is clear that the major source of air pollution in metropolitan cities, accounting for up to 80% of total air pollution, is **Option A: Automobile and traffic transportation**.

5. **Final Answer**: The correct answer is **A) Automobile and traffic transportation**.

---