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 mammals independent and tough suspension for teeth is provided by 
Select and explain. 
A. Alveolar sockets, B. Cementum, C. Gubernacular cords, D. Periodontal membrane
D: Periodontal membrane
Answer: D: Periodontal membrane 
Explanation: None