Lichens are senstive to

Options

A. Noise pollution
B. Air pollution
C. Water pollution
D. Nuclear pollution

Answer

### Step-by-Step Solution:

1. **Understanding Lichens**: Lichens are symbiotic organisms made up of fungi and algae or cyanobacteria. They are often found in various environments and are known for their sensitivity to environmental changes.

2. **Identifying the Context**: The question asks about what lichens are sensitive to, with multiple choice options provided:
- A) Noise pollution
- B) Air pollution
- C) Water pollution
- D) Nuclear pollution

3. **Defining Bio-indicators**: Lichens are referred to as bio-indicators. This means that they can indicate the health of the environment, particularly in relation to pollution levels.

4. **Analyzing Pollution Types**:
- **Noise Pollution**: While it affects many species, lichens are not particularly sensitive to noise.
- **Water Pollution**: Lichens can be affected by water quality, but they are primarily indicators of air quality.
- **Nuclear Pollution**: This type of pollution is less relevant to lichens as they are not specifically sensitive to radiation.
- **Air Pollution**: Lichens are highly sensitive to air pollutants, especially sulfur dioxide and other airborne toxins.

5. **Conclusion**: Given that lichens show a decline in population with increased air pollution, particularly due to sulfur dioxide, the correct answer is **B) Air pollution**.

### Final Answer:
Lichens are sensitive to **air pollution**.

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