This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Skin
[{'content': 'Black piedra is caused by ? \nSelect and explain. \nA. Piedraia hoae, B. Trichosporon asahi, C. Trichosporon ovoides, D. Trichosporon inkin', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Piedraia hoae Piedra is an asymptomatic superficial fungal infection of the hair shaft also known as trichomycosis nodu- laris. Black piedra is caused by Piedraia hoae, whereas white piedra is caused by pathogenic species of the Trichosporon genus, namely Trichosporon asahii, Trichosporon ovoides, Trichosporon inkin, Trichosporon mucoides, Trichosporon asteroides, and Trichosporon cutaneum.", 'role': 'assistant'}]