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': 'In IVP, Adder head appearance is seen in: \nSelect and explain. \nA. Polycystic kidney, B. Horse shoe kidney, C. Ureterocele, D. Hydronephrosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ureterocele is a cystic dilatation of the distal ureter. Cobra head or Adder head appearance is diagnostic of ureterocele. Spider leg appearance in polycystic kidney. Ref: Bailey & Love, 25th Edition, Page 1290', 'role': 'assistant'}]