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
[{'content': 'Adder – head appearance on voiding cystourethrogram in bladder is feature of – \nSelect and explain. \nA. Horse shoe kidney, B. VUR, C. Ureterocele, D. Carcinoma of bladder', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]