**Core Concept**
Tinea pedis, also known as athlete's foot, is a type of fungal infection that affects the skin on the feet. It is caused by dermatophytes, a group of fungi that feed on keratin, a protein found in skin, hair, and nails.

**Why the Correct Answer is Right**
Tinea pedis is primarily caused by three types of dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum. These fungi infect the skin on the feet, leading to symptoms such as itching, cracking, and scaling. The infection typically starts between the toes, where the warm, moist environment is ideal for fungal growth.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect, as the causative agent of ringworm, a different type of fungal infection, is typically Trichophyton tonsurans or Microsporum canis.
**Option B:** This option is incorrect, as Aspergillus is a type of fungus that causes aspergillosis, a different type of fungal infection.
**Option C:** This option is incorrect, as Candida is a type of yeast that causes candidiasis, a different type of fungal infection.

**Clinical Pearl / High-Yield Fact**
Tinea pedis is contagious and can be spread through direct contact with an infected person or by sharing personal items such as towels or shoes. It is essential to practice good hygiene and wear clean socks and shoes to prevent the spread of the infection.

**Correct Answer: C. Epidermophyton floccosum**