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': 'Rib notching is seen in all except-like diagnosis is - \nSelect and explain. \nA. Coarctation of aorta, B. Classical blalock tausing operation, C. IVC obstruction, D. Neurofibromatosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]