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
Cervical restorations fail mostly due to 
Select and explain. 
A. Inadequate moisture control, B. Marginal gingivitis, C. Cuspal flexure, D. All the above
A: Inadequate moisture control
Answer: A: Inadequate moisture control 
Explanation: None