Concept:Foot and mouth disease is a highly contagious viral infection of cattle and other cloven-hoofed animals.Explanation:The disease is caused by a virus, not a fungus, nematode, or bacterium.It spreads quickly among cattle, sheep, goats, and pigs through direct contact or contaminated materials.The causative agent belongs to the genus Aphthovirus.Since it is viral, antibiotics are ineffective against it.Answer:A. virus