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
The function of a root canal sealer is: 
Select and explain. 
A. To fill the gap between the tooth and the filling, B. As an antiseptic, C. Aids in healing, D. Provide strength
A: To fill the gap between the tooth and the filling
Answer: A: To fill the gap between the tooth and the filling 
Explanation: None