Which of the following is mismatch?

Options

A. Leprosy - Bacterial disease
B. AIDS - Bacterial disease
C. Malaria - Protozoan disease
D. Elephantiasis - Helminthic disease

Explanation

To determine which of the following pairs is a mismatch, we will analyze each option one by one.

### Step-by-Step Solution:

1. **Analyze the first option: Leprosy**
- Leprosy is matched with a bacterial disease.
- Leprosy is caused by *Mycobacterium leprae*, which is indeed a bacterium.
- **Conclusion:** This pair is correctly matched.

2. **Analyze the second option: AIDS**
- AIDS is matched with a bacterial disease.
- AIDS is caused by the Human Immunodeficiency Virus (HIV), which is a virus, not a bacterium.
- **Conclusion:** This pair is mismatched.

3. **Analyze the third option: Malaria**
- Malaria is matched with a protozoan disease.
- Malaria is caused by *Plasmodium*, which is a protozoan.
- **Conclusion:** This pair is correctly matched.

4. **Analyze the fourth option: Lymphatic Filariasis (Elephantiasis)**
- Lymphatic Filariasis is matched with a helminthic disease.
- This disease is caused by *Wuchereria bancrofti*, which is a parasitic worm (helminth).
- **Conclusion:** This pair is correctly matched.

### Final Conclusion:
The mismatch is found in the second option: AIDS is incorrectly matched with a bacterial disease. It should be matched with a viral disease.