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': 'Oral retinoid is indicated in the treatment of: \nSelect and explain. \nA. Acne vulgaris, B. Pemphigus vulgaris, C. Lupus vulgaris, D. Erythema multiforme', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Acne vulgaris', 'role': 'assistant'}]