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: Medicine
[{'content': 'Notching of ribs occurs in all EXCEPT \nSelect and explain. \nA. Coarctation of aorta, B. Neurofibromatosis, C. Hypothyroidism, D. Osteogenesis imperfecta', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]