The correct answer is option 2: Fungus. Athlete`s Foot disease, also known as tinea pedis, is a common fungal infection that affects the skin on the feet. Fungi are microscopic organisms that can live on the skin, nails, and hair. They thrive in warm, moist environments, making the feet an ideal location for their growth.

Bacteria (option 1) are single-celled organisms that can cause various infections, but they are not responsible for causing Athlete`s Foot.

Protozoa (option 3) are single-celled organisms that can cause diseases like malaria and amoebic dysentery, but they are not associated with Athlete`s Foot.

Viruses (option 4) are infectious agents that require a host cell to reproduce and cause diseases like the common cold, flu, and HIV. However, Athlete`s Foot is not caused by a virus.

Therefore, the most accurate answer is option 2: Fungus, as fungi are the organisms responsible for causing Athlete`s Foot.