This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Occupational Health, Subject name: Social & Preventive Medicine
[{'content': 'Most common heavy metal poisoning in industrial workers in - \nSelect and explain. \nA. Lead, B. Arsenic, C. Mercury, D. Cadmium', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Lead * More idustrial workers are exposed to lead than any other toxic metal.", 'role': 'assistant'}]