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: Medicine
[{'content': 'A 16-year-old boy is found to have hypertension on routine evaluation. On examination, the blood pressure in his arms is higher than in his legs by more than 10 mm Hg. Which of the following is the most likely diagnosis? \nSelect and explain. \nA. aortic insufficiency, B. coarctation of the aorta, C. normal variant, D. ventricular aneurysm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Besides coarctation of the aorta, aortic occlusive disease, dissection of the aorta, and abdominal aneurysm may lead to differential blood pressure in arms and legs. Coarctation is the third most common form of congenital cardiac disease. One-third of the patients will be hypertensive. The femoral pulses are weak, delayed, and even absent.', 'role': 'assistant'}]