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 during access opening of a maxillary incisor perforation occurs on labial surface just above CEJ, reason is? 
Select and explain. 
A. Inability to assess the lingual inclination of crown to root, B. Inability to assess the facial inclination of crown to root, C. All of the above, D. None of the above
A: Inability to assess the lingual inclination of crown to root
Answer: A: Inability to assess the lingual inclination of crown to root 
Explanation: None