“Athlete’s Foot” is a disease caused by

“Athlete’s foot” is the common name for tinea pedis, a superficial skin infection of the feet caused by dermatophyte fungi. These fungi (for example Trichophyton species) invade keratinized tissues such as the outer skin, nails and hair and are the usual agents of tinea infections of the foot and nails [1]. Clinical guidance and public-health descriptions classify tinea pedis explicitly as a fungal (dermatophyte) infection and note its transmission in warm, moist environments like locker rooms, showers and pools where fungi thrive [1]. Therefore the correct causal group is fungi.

Sources

1. [1] https://www.cdc.gov/ringworm/about/index.html