**Answer:**

Foot and Mouth Disease (FMD) is a highly contagious viral disease that affects cloven-hoofed animals such as cattle, pigs, sheep, and goats. It is caused by a virus belonging to the Aphthovirus genus of the Picornaviridae family.

**Explanation:**

**1. Foot and Mouth Disease (FMD)**
- Foot and Mouth Disease is a viral disease that affects cloven-hoofed animals like cattle, pigs, sheep, and goats.
- It is highly contagious and can spread rapidly among susceptible animals.
- The disease is characterized by the appearance of fever, blisters, and erosions on the tongue, lips, gums, and hooves of affected animals.
- FMD can have severe economic consequences for the livestock industry due to production losses, trade restrictions, and control measures.

**2. Micro-organisms causing Foot and Mouth Disease**

The correct answer to the question is option 'c) Virus'. Foot and Mouth Disease is caused by a virus, not bacteria, fungi, or protozoa. Here's some information about the virus responsible for FMD:

- The virus that causes Foot and Mouth Disease belongs to the Aphthovirus genus of the Picornaviridae family.
- It is a small, single-stranded RNA virus with a protein coat.
- There are seven different serotypes of the FMD virus, namely O, A, C, Asia 1, SAT 1, SAT 2, and SAT 3.
- Each serotype can further be divided into multiple subtypes.
- The virus is highly contagious and can spread through direct contact with infected animals, their secretions, or contaminated materials.
- It can also be transmitted through airborne droplets or contaminated feed and water.
- The FMD virus has a high rate of mutation, which contributes to the diversity of strains and the difficulty in developing effective vaccines.

In conclusion, Foot and Mouth Disease in animals is caused by a virus belonging to the Aphthovirus genus of the Picornaviridae family. It is highly contagious and can have significant economic consequences for the livestock industry.