This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Heart & Pericardium, Subject name: Surgery
Notching of ribs occurs in what? SELECT ONE. 
Select and explain. 
A. A double aortic arch, B. Tetralogy of Fallot, C. PDA, D. Coarctation of the aorta
D: Coarctation of the aorta
Answer: D: Coarctation of the aorta 
Explanation: In the presence of coarctation of the aorta, left ventricular enlargement, hypertrophy, and failure to develop occur. As the child grows, collaterals develop between the subclavian artery and the aorta via the intercostal and internal thoracic vessels. In children older than 8 years of age, the intercostal arteries cause typical notching on the inferior margin of the ribs.