Find out the correctly matched option of the causative agent and their disease.

Options

A. Prion-Bovine Spongiform Encephalopathy
B. Virus - Citrus Canker disease
C. Viroids - Cr- Jacob disease in human
D. Bacteria- small pox

Answer

To solve the question of finding the correctly matched option of the causative agent and their disease, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the first option: Prions and Bovine Spongiform Encephalopathy**
- Prions are infectious agents composed of protein that can cause neurodegenerative diseases.
- Bovine spongiform encephalopathy (BSE), also known as mad cow disease, is indeed caused by prions.
- **Conclusion**: This pair is correctly matched.

2. **Identify the second option: Virus and Citrus Canker Disease**
- Citrus canker disease is not caused by a virus; it is caused by the bacterium Xanthomonas citri.
- **Conclusion**: This pair is incorrectly matched.

3. **Identify the third option: Viroid and Creutzfeldt-Jakob Disease**
- Creutzfeldt-Jakob disease is a neurodegenerative disorder caused by prions, not viroids.
- **Conclusion**: This pair is incorrectly matched.

4. **Identify the fourth option: Bacteria and Smallpox**
- Smallpox is a viral disease caused by the variola virus, not by bacteria.
- **Conclusion**: This pair is incorrectly matched.

### Final Conclusion:
The only correctly matched option is:
- **Prions and Bovine Spongiform Encephalopathy**.