Use of lichens in case of pollution is

Options

A. Treatement of pollutants water
B. Bioindicators of pollution
C. Promote pollution
D. Lichens have no relatation with pollution

Answer

**Step-by-Step Solution:**

1. **Understanding Lichens**: Lichens are symbiotic organisms made up of fungi and algae or cyanobacteria. They are sensitive to environmental changes, particularly air quality.

2. **Role of Lichens in Pollution**: Lichens are known to be affected by pollution, especially air pollution. Their presence or absence can indicate the level of pollution in an area.

3. **Bioindicators Defined**: A bioindicator is a living organism that gives us an idea of the health of an ecosystem or the level of pollution in the environment.

4. **Lichens as Bioindicators**: When pollution levels increase, particularly air pollution, the population of lichens tends to decline. This decline is significant because lichens are sensitive to pollutants like sulfur dioxide and nitrogen oxides.

5. **Conclusion**: Therefore, the correct answer to the question regarding the use of lichens in the case of pollution is that they serve as bioindicators of pollution.

**Final Answer**: Option B - Lichens are bioindicators of pollution.

---