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
Rest position of mandible is established by muscles and 
Select and explain. 
A. Pressure, B. Gravity, C. Temperature, D. None of the above
B: Gravity
Answer: B: Gravity 
Explanation: The postural position of mandible in man is maintained by tonic activity in the elevator musculature opposing gravitational forces.