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': 'Comedones are characteristic of: September 2004 \nSelect and explain. \nA. Psoriasis, B. Acne vulgaris, C. Lichen planus, D. Pemphigus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B i.e. Acne vulgaris', 'role': 'assistant'}]