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
Feature of aging periodontium is 
Select and explain. 
A. Lacunae in bone and cementum, B. Increased cell size, C. Increased cell number, D. Scalloping of cementum & alveolar bone surface
D: Scalloping of cementum & alveolar bone surface
Answer: D: Scalloping of cementum & alveolar bone surface 
Explanation: None