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
Rib notching is seen in all except-like diagnosis is - 
Select and explain. 
A. Coarctation of aorta, B. Classical blalock tausing operation, C. IVC obstruction, D. Neurofibromatosis
C: IVC obstruction
Answer: C: IVC obstruction 
Explanation: None