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
Ratio of upper anterior facial height to lower anterior facial height is: 
Select and explain. 
A. 55:45:00, B. 60:40:00, C. 40:60, D. 45:55:00
D: 45:55:00
Answer: D: 45:55:00 
Explanation: The ratio of upper anterior facial height and lower anterior facial height ratio is 45:55. It decreases with age.
N-Sn occupying 45% and  Sn-Gn 55% of the total height.