Which of the following are highly sensitive to oxide of sulphur and are indicators of sulphur pollution ?

Options

A. Equisetum
B. Lichen
C. Eucalyptus
D. Eichhornia

Answer

To solve the question regarding which organisms are highly sensitive to oxides of sulfur and serve as indicators of sulfur pollution, we can follow these steps:

### Step 1: Understand the Organisms Listed
We have three organisms to consider:
1. Equisetum (a genus of plants commonly known as horsetails)
2. Eucalyptus (a genus of flowering trees and shrubs)
3. Echinodorus (a genus of aquatic plants, often referred to as sword plants)

### Step 2: Identify Sensitive Organisms
Among these organisms, we need to identify which ones are sensitive to sulfur oxides, particularly sulfur dioxide (SO2).

### Step 3: Research Characteristics of Each Organism
- **Equisetum**: While it is a plant that can be found in various environments, it is not particularly known for sensitivity to sulfur pollution.
- **Eucalyptus**: This genus is known for its resilience and adaptability to various environments, including polluted areas. It is not a strong indicator of sulfur pollution.
- **Lichens**: Although not listed in the options, lichens are well-known indicators of air quality and are highly sensitive to sulfur dioxide. They do not thrive in areas with high levels of sulfur pollution.

### Step 4: Conclusion
Based on the information gathered, the organism that is highly sensitive to oxides of sulfur and serves as an indicator of sulfur pollution is **Lichens**. However, since lichens are not one of the options provided, we can conclude that none of the listed organisms (Equisetum, Eucalyptus, Echinodorus) are strong indicators of sulfur pollution.

### Final Answer
None of the provided options (Equisetum, Eucalyptus, Echinodorus) are highly sensitive to oxides of sulfur and serve as indicators of sulfur pollution.

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