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
Greatest potential hazard of mercury toxicity occurs due to: 
Select and explain. 
A. Skin contact with mercury, B. Inhalation of mercury vapours, C. During amalgam restoration, D. Ingestion of amalgam scrap during removal
B: Inhalation of mercury vapours
Answer: B: Inhalation of mercury vapours 
Explanation: None