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: Dental
[{'content': "The 'Key hole' pattern appearance in the cross section is feature of \nSelect and explain. \nA. Aprismatic enamel, B. Prismatic enamel, C. Intertubular dentin, D. Intratubular dentin", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]