Causative organism of foot and mouth disease of cattle:

Options

A. virus
B. bacteria
C. protozoan
D. fungi

Explanation

**Step-by-Step Solution:**

1. **Understanding the Disease**: Foot and mouth disease (FMD) is a contagious viral disease that primarily affects livestock, particularly cattle.

2. **Identifying the Causative Agent**: The causative organism of foot and mouth disease is a virus.

3. **Naming the Virus**: The specific virus responsible for foot and mouth disease is referred to as the "foot and mouth disease virus" or FMD virus.

4. **Classification of the Disease**: Since FMD is caused by a virus, it is classified as a viral disease, distinguishing it from diseases caused by bacteria, protozoa, or fungi.

5. **Conclusion**: Therefore, the causative organism of foot and mouth disease in cattle is the foot and mouth disease virus (FMD virus).

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