A patient schedules a clinic visit after finding a patch of discolored skin on her back. She is very concerned about where this came from and believes it may have appeared after she used a gift certificate for a tanning salon. She had never used a UV tanning bed before, and she says she thinks there's a history of cancer on her mother-in-law's side of the family. After an examination, you reassure the woman that the physical diagnosis is indeed a skin problem that may have been picked up at the tanning salon, but it is a non-serious condition that:

a. Is a self-limiting viral infection that will only cause KOH
b. Is an outbreak of the skin flora bacterium Staphylococcus epidermidis
c. Is a simple parasite infection known as "athlete's back"
d. Is a fungal infection of the skin known as "tinea versicolor"