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: Surgery
A painless, fluid filled retention cyst appearing in the area of recent dental treatment may be the result of 
Select and explain. 
A. Failure of absorption of the anaesthetic, B. Allergic reaction of agents employed, C. Infection occurred during treatment., D. Injury to salivary gland.
D: Injury to salivary gland.
Answer: D: Injury to salivary gland. 
Explanation: None