Litmus is a natural dye obtained from :

Options

A. virus
B. actinomycetes
C. fungi
D. lichens

Explanation

To determine the source of litmus, we can follow these steps:

1. **Understand what litmus is**: Litmus is a natural dye that is commonly used as a pH indicator. It changes color in response to the acidity or alkalinity of a solution.

2. **Identify potential sources of natural dyes**: The options given are virus, actinomycetes, fungi, and lichens. We need to evaluate each option to see which one is a known source of natural dyes.

3. **Evaluate the options**:
- **Virus**: Viruses are infectious agents and do not produce dyes. Therefore, this option is incorrect.
- **Actinomycetes**: These are a type of bacteria and are not known for producing natural dyes. Thus, this option is also incorrect.
- **Fungi**: While some fungi can produce pigments, they are not the primary source of litmus. This option is not correct either.
- **Lichens**: Lichens are symbiotic organisms made up of fungi and algae or cyanobacteria. They are known to produce a variety of natural dyes, including litmus.

4. **Conclusion**: Based on the evaluation, the correct answer is that litmus is a natural dye obtained from lichens.

**Final Answer**: Litmus is a natural dye obtained from lichens.

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