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: Pediatrics
Inferior rib notching is present in 
Select and explain. 
A. TAPVC, B. Coarctation of aorta, C. Fallot's tetralogy, D. Ventricular septal defect
B: Coarctation of aorta
Answer: B: Coarctation of aorta 
Explanation: Causes of rib notching ae: - A) Inferior surface
1) Arterial
i) Coarctation of aorta Bilateral Rib notching is seen on the lower border of 3 rd to 8th ribs. Rib notching is absent in the 1st & 2nd ribs. Rib notching is usually present after the age of 7 years.
ii) Aortic thrombosis (aortic obstruction) or aortitis.
iii) Subclavian obstruction after Blalock operation for Fallot’s tetralogy (Taussig Blalock operation).
iv) Pulmonary oligemia Pulmonary atresia,
1)TOF, absent pulmonary artery.
2) Venous : - SVC obstruction
3) Arteriovenous : - Pulmonary arteriovenous malformation, chest wall arteriovenous malformation.
4) Neurogenic : - Neurofibromatosis.
B) Superior surface
1) Connective tissue diseases: - SLE, Scleroderma, RA, Sjogren’s syndrome.
2) Metabolic : - Hyperparathyroidism
3) Miscellaneous : - Neurofibromatosis, Restrictive lung disease, Poliomyelitis, Marfan’s syndrome, progeria, Osteogenesis imperfecta.