Find the incorrectly matched:

Options

A. `{:("Disease","Casual orgnism"),("Black of crucifers","Bacteria"):}`
B. `{:("Disease","Casual orgnism"),("Brown rust of wheat","Fungi"):}`
C. `{:("Disease","Casual orgnism"),("Late blight of Potato","Virus"):}`
D. `{:("Disease","Casual orgnism"),("Red rot of sugarcane","Fungi"):}`

Answer

To solve the question of finding the incorrectly matched disease and its causal organism, we will analyze each option provided.

### Step-by-Step Solution:

1. **Identify the Options**: We have four options, each consisting of a disease (A) and its causal organism (B).

2. **Examine Option 1**:
- **Disease**: Black Rot of Crucifers
- **Causal Organism**: Xanthomonas
- **Analysis**: Black Rot of Crucifers is indeed caused by the bacterium Xanthomonas campestris.
- **Conclusion**: This option is correctly matched.

3. **Examine Option 2**:
- **Disease**: Brown Rust of Wheat
- **Causal Organism**: Puccinia triticina
- **Analysis**: Brown Rust of Wheat is caused by the fungus Puccinia triticina.
- **Conclusion**: This option is correctly matched.

4. **Examine Option 3**:
- **Disease**: Late Blight of Potato
- **Causal Organism**: Virus
- **Analysis**: Late Blight of Potato is caused by the fungus Phytophthora infestans, not a virus.
- **Conclusion**: This option is incorrectly matched.

5. **Examine Option 4**:
- **Disease**: Red Rot of Sugarcane
- **Causal Organism**: Colletotrichum
- **Analysis**: Red Rot of Sugarcane is indeed caused by the fungus Colletotrichum falcatum.
- **Conclusion**: This option is correctly matched.

6. **Final Conclusion**: The incorrectly matched option is Option 3, where the causal organism for Late Blight of Potato is incorrectly identified as a virus instead of the correct fungus.

### Answer:
The incorrectly matched option is **Option 3**: Late Blight of Potato - Virus.

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