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': 'Dental surveyor is used to \nSelect and explain. \nA. Measure resiliency of tissues, B. Indicate relative parallelism between two teeth, C. To determine primary stress bearing area, D. To determine depth of undercut', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]