Which of the following is used as an atmospheric pollution indicator?

Options

A. Lepidoptera
B. Lichens
C. Lycopersicon
D. Lycopodium

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an indicator of atmospheric pollution. This means we need to identify an organism or substance that can signal the presence of pollutants in the atmosphere.

2. **Identifying Potential Indicators**: In environmental science, certain organisms are known to be sensitive to air quality. One such group is lichens, which are often used as bioindicators.

3. **Defining Lichens**: Lichens are a symbiotic relationship between fungi and algae. This means they consist of two different organisms living together in a mutually beneficial way.

4. **Sensitivity to Pollution**: Lichens are particularly sensitive to air pollution, especially to sulfur dioxide (SO2). This sensitivity makes them reliable indicators of air quality.

5. **Conclusion**: Based on the information gathered, lichens can be identified as atmospheric pollution indicators due to their sensitivity to pollutants like sulfur dioxide.

**Final Answer**: Lichens are used as atmospheric pollution indicators.

---