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': '"Guiding planes" relates to: \nSelect and explain. \nA. Path of insertion, B. Means of retention, C. Extent of undercuts, D. Tilt of abutment teeth', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]