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: Radiology
Which of the following causes rib notching on Xray- 
Select and explain. 
A. Coarctation of aorta, B. SVC occlusion, C. Modified Blalock Taussing shunt, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Ans, is 'd' i.e., All of the above Rib notching o "Rib notches" are peripheral, sharply circumscribed osteolytic lesion on superior or inferior surface of ribs, o Causes of rib notching ae : - Inferior surface Arterial Coarctation of aortaBilateral Rib notching is seen on the lower border of 3rd to 8th ribs. Rib notching is absent in the 1st & 2nd ribs. Rib notching is usually present after the age of 7 years. Aortic thrombosis (aortic obstruction) or aortitis. Subclavian obstruction after Blalock operation for Fallot's tetralogy (Taussig Blalock operation. Pulmonary oligemiaPulmonary' atresia, TOF, absent pulmonary artery. Venous : - SVC obstruction Arteriovenous: - Pulmonary arteriovenous malformation, chest wall arteriovenous malformation. Neurogenic: - Neurofibromatosis. Superior surface Connective tissue diseases : - SLE, Scleroderma, RA, Sjogren's syndrome. Metabolic : - Hyperparathyroidism Miscellaneous : Neurofibromatosis, Restrictive lung disease, Poliomyelitis, Marfan's syndrome, progeria. Osteogenesis imperfecta.