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': 'Commonest cause of sustained severe hypeension in children \nSelect and explain. \nA. Endocrine causes, B. Coarctation of aoa, C. Renal parenlchyma disease, D. Pheochromocytoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The chief causes of severe sustained hypeension identified included chronic glomerulonephritis , obstructive uropathy , reflux nephropathy , thrombotic microangiopathy and renovascular disease . ref:Harrison&;s principles of internal medicine,ed 18,pg no', 'role': 'assistant'}]