This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Pediatrics
[{'content': "Inferior Rib notching is seen in? \nSelect and explain. \nA. Coarctation of aorta, B. Marfan's syndrome, C. Rickets, D. SLE", 'role': 'user'}, {'content': "Answer: A \nExplanation: a. Coarctation of aorta(Ref: Nelson's 20/e p 2205)Notching of the inferior border of 3rd - 9th ribs from pressure erosion by enlarged collateral vessels, is usually seen beyond the age of 3 years, in a child with coarctation of aorta.", 'role': 'assistant'}]