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 anteroposterior occlusal plane should be parallel to: \nSelect and explain. \nA. Ala tragus line, B. Camper's line, C. Bromel's line., D. All of the above.", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]