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: Radiology
Most common cause of renovascular hypertension in children and young adults 
Select and explain. 
A. Atherosclerotic disease, B. Fibromuscular dysplasia, C. Ectopic kidney, D. PCKD
B: Fibromuscular dysplasia
Answer: B: Fibromuscular dysplasia 
Explanation: None