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: Surgery
[{'content': 'A 3 year old girl presents with recurrent UTI. On USG shows hydronephrosis with filling defect and negative shadow of bladder with no ectopic orifice- \nSelect and explain. \nA. Vesicoureteric reflux, B. Hydronephrosis, C. Ureterocele, D. Sacrococcygeal teratoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]