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
After removal of periodontal pack after a week of surgery, you see a large round elevated granulation tissue. It is most likely due to: 
Select and explain. 
A. Allergy to components in the pack, B. Normal finding, C. Incomplete calculus removal, D. Mechanical irritation due to periodontal pack
C: Incomplete calculus removal
Answer: C: Incomplete calculus removal 
Explanation: None