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': 'In a class II cavity in an incisor the retentive points are placed: \nSelect and explain. \nA. At the DEJ, B. In the dentin, C. In the axial wall, D. Never on labial or Lingual walls', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]