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
Commonest cause of sustained severe hypeension in children 
Select and explain. 
A. Endocrine causes, B. Coarctation of aoa, C. Renal parenlchyma disease, D. Pheochromocytoma
C: Renal parenlchyma disease
Answer: C: Renal parenlchyma disease 
Explanation: 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