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
If a patient has gingival recession, how far should the gutta percha be trimmed back before sealing the coronat area? 
Select and explain. 
A. 1 mm below the level of the recession, B. 1 mm below the ACJ, C. 1 mm below the canal opening, D. 1 mm below the roof of pulpal chamber
A: 1 mm below the level of the recession
Answer: A: 1 mm below the level of the recession 
Explanation: None