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: Dental
[{'content': 'Stainless steel crowns are contraindicated in: \nSelect and explain. \nA. Medically compromised patient, B. After endodontic therapy, C. Rampant caries, D. Amelogenesis imperfecta', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]