This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mycology, Subject name: Microbiology
[{'content': 'Favus is caused by: \nSelect and explain. \nA. Blockage of sebaceous duct, B. Staph aureus, C. Trichophyton schoenleinii, D. Trichophyton concentricum', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Favus is a form of tinea capitis in which there is formation of crusting lesions (scutula) in the involved region of the infection. It is most often caused by T. schoenleinii.', 'role': 'assistant'}]