This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Toxicology - 1, Subject name: Forensic Medicine
[{'content': 'Which of the following is a vesicant \nSelect and explain. \nA. Lewisite, B. Sarin, C. Chlorine, D. Chloracetophenone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Lewisite - VESICANT Sarin- NERVE GAS Chlorine - ASPHYXIANT Chloracetophenone - TEAR GAS', 'role': 'assistant'}]