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: Pathology
[{'content': "Failure of Hertwig's epithelial sheath diaphragm to investigate the proper horizontal level leads to: \nSelect and explain. \nA. Taurodontism., B. Dentin dysplasia., C. Pulp polyp., D. Amelogenesis imperfecta.", 'role': 'user'}, {'content': 'Answer: A \nExplanation: TAURODONTISM\n\nAlso called Bull-like teeth.\nOriginally described by Sir Arthur Keith in 1913 to describe a condition in which the body of the tooth is\xa0enlarged at the expense of roots.\nCaused by the failure of Hertwig’s epithelial sheath diaphragm to investigate the proper horizontal level.', 'role': 'assistant'}]