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
The wax "working bite" prior to functional appliance construction is made primary with the intention of 
Select and explain. 
A. Providing a record of occlusion, B. Registering desired mandible position, C. To relax the jaw muscles, D. All of the above
B: Registering desired mandible position
Answer: B: Registering desired mandible position 
Explanation: Mechanism of action of working bite:

Displaces mandible from its rest position causing stretching of the muscles attached to mandible.
The reﬂex activity tends to restore mandible to a postural position that was determined by the unstretched muscles.
Most construction or working bites are taken at a vertical dimension beyond freeway space. This increases vertical dimension and also displace the mandible in the sagittal and transverse planes.