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': 'Rest position of mandible is established by muscles and \nSelect and explain. \nA. Pressure, B. Gravity, C. Temperature, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The postural position of mandible in man is maintained by tonic activity in the elevator musculature opposing gravitational forces.', 'role': 'assistant'}]