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': 'Wax crayons contains \nSelect and explain. \nA. Lead, B. Para nitro aniline, C. Beryllium, D. Nitrobenzene', 'role': 'user'}, {'content': 'Answer: B \nExplanation: #NAME?', 'role': 'assistant'}]