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
[{'content': 'The maximum amount of mercury vapour allowed in the work place: \nSelect and explain. \nA. 0.005 mg/m3, B. 0.5 mg/m3, C. 0.05 mg/m3, D. 0.025 mg/m3', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]