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
While recording the rest position of the mandible, the patient’s head position should be 
Select and explain. 
A. Head should be upright and unsupported, B. Head should be supported by the head rest, C. Patient should be lying in repose position, D. The neck should be extended
A: Head should be upright and unsupported
Answer: A: Head should be upright and unsupported 
Explanation: In this position, action of the muscles that regulate mandibular position is equalized and mandible is free of any undue pull of any muscle.