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 ratio of skeletal: dental expansion obtained finally after Rapid palatal expansion is: 
Select and explain. 
A. 4:01, B. 3:01, C. 2:01, D. 1:01
D: 1:01
Answer: D: 1:01 
Explanation: None