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: Surgery
How many Champy's osteosynthesis lines exist behind and in the front end of mental foramen: 
Select and explain. 
A. 2 ahead of and 1 behind the mental foramen., B. 1 ahead of and 2 behind the mental foramen., C. 2 ahead of and 2 behind the mental foramen., D. 1 ahead of and 1 behind the mental foramen.
A: 2 ahead of and 1 behind the mental foramen.
Answer: A: 2 ahead of and 1 behind the mental foramen. 
Explanation: None