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: Radiology
Superior rib notching is/are caused by: 
Select and explain. 
A. Hyperparathyroidism, B. Poliomyelitis, C. Marfan syndrome, D. All
D: All
Answer: D: All 
Explanation: A, B, C, i.e. Hyperparathyroidism, Poliomyelitis, Marfan syndome