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
After mixed dentition stage the arch length from first molar to first molar usually: (Or) The arch length from mixed dentition to permanent dentition 
Select and explain. 
A. Remains same, B. Increases, C. Decreases, D. Doubles
C: Decreases
Answer: C: Decreases 
Explanation: None