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': 'All are true statements regarding us, EXCEPT: \nSelect and explain. \nA. It is a form of Tinea capitis, B. It is caused by Tinea schoenlein, C. It causes cicatricial alopecia, D. It is characterised by presence of dark brown to black nodules cemented to the hair shaft', 'role': 'user'}, {'content': "Answer: D \nExplanation: It is characterised by yellowish cup shaped crests called scutula. Dark brown/black nodules are seen as black piedra caused by piedraia hoae.Ref: Rook's Textbook of Dermatology, 8th Edition", 'role': 'assistant'}]