In poultry, coccidiosis is caused by

Options

A. Virus
B. Fungus
C. Helminth parasite
D. Protozoan

Answer

### Step-by-Step Solution:

1. **Understanding Coccidiosis**:
- Coccidiosis is a disease that affects poultry and is important to identify the causative agent.

2. **Identifying the Options**:
- The options given are virus, fungus, helminth parasite, and protozoa.

3. **Researching the Causative Agent**:
- Coccidiosis is known to be caused by a specific type of microorganism.

4. **Determining the Correct Microorganism**:
- After researching, it is found that coccidiosis is caused by protozoa.

5. **Classifying the Protozoa**:
- The protozoa responsible for coccidiosis belong to the phylum **Apicomplexa**.

6. **Identifying the Family and Genus**:
- Within the phylum Apicomplexa, the family is **Eimeriidae**, and the most common species affecting poultry belong to the genus **Eimeria**.

7. **Conclusion**:
- Therefore, coccidiosis in poultry is caused by protozoa, specifically from the genus Eimeria.

### Final Answer:
Coccidiosis in poultry is caused by protozoa (specifically from the genus Eimeria).

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