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
In endodontic-periodontal lesion pulpal necrosis 
Select and explain. 
A. Follows periodontal changes, B. Precedes periodontal changes, C. Impedes periodontal changes, D. All of the above
B: Precedes periodontal changes
Answer: B: Precedes periodontal changes 
Explanation: None