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 vertical dimension when the mandible and muscles involved are in physiological function of speech is called as: 
Select and explain. 
A. Closest speaking space., B. Freeway space., C. Vertical dimension., D. None.
A: Closest speaking space.
Answer: A: Closest speaking space. 
Explanation: None