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 most frequent complaint of patients shortly after amalgam restorations are placed is: 
Select and explain. 
A. Pain on percussion, B. An open contact point, C. Cold sensitivity, D. Numbness around the gingiva
C: Cold sensitivity
Answer: C: Cold sensitivity 
Explanation: None