Which of the following is the ''bird flu virus'' ?

Options

A. `H5N1`
B. Haemophilus influenzae
C. HIV
D. Rhino virus

Explanation

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks which of the given options is the "bird flu virus."

2. **List the Options**: The options provided are:
- H5N1
- Haemophilius influenzae
- HIV
- Rhinovirus

3. **Analyze Each Option**:
- **H5N1**: This is known to cause avian influenza, commonly referred to as bird flu. It is a subtype of the influenza A virus.
- **Haemophilius influenzae**: This is not a virus; it is a type of bacteria known as Pfeiffer's bacillus and is gram-negative.
- **HIV**: This stands for Human Immunodeficiency Virus, which causes AIDS (Acquired Immunodeficiency Syndrome) and is not related to bird flu.
- **Rhinovirus**: This virus is responsible for causing the common cold and is not associated with avian influenza.

4. **Conclusion**: Based on the analysis, the correct answer to the question "Which of the following is the bird flu virus?" is **H5N1**.

5. **Final Answer**: H5N1 is the bird flu virus.

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