This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
[{'content': 'What is column of beini in kidney ? \nSelect and explain. \nA. Renal tumour, B. Tongue like papillary projection, C. Calculus, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The renal column (or Bein column , or column of Bein ) is a medullary extension of the renal coex in between the renal pyramids. The hyperophy of these columns is a benign condition sometimes mistaken for a renal tumor .', 'role': 'assistant'}]