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 incisive papilla in the edentulous maxillary arch acts as a guideline to proper placement of the maxillary central incisors. The central incisors are generally found to be ________ mm anterior to a Line bisecting the incisive papilla: 
Select and explain. 
A. 8 to 10mm, B. 6 to 8mm, C. 4 to 6mm, D. 5 to 7mm
A: 8 to 10mm
Answer: A: 8 to 10mm 
Explanation: None