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 maximum amount of mercury vapour allowed in the work place: 
Select and explain. 
A. 0.005 mg/m3, B. 0.5 mg/m3, C. 0.05 mg/m3, D. 0.025 mg/m3
C: 0.05 mg/m3
Answer: C: 0.05 mg/m3 
Explanation: None