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: Forensic Medicine
[{'content': 'Jet black pigmentation of tongue with tactile and visual hallucination is feature of which poisoning- \nSelect and explain. \nA. Cocaine, B. Arsenic, C. Cannabis, D. Heroin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Black pigmentation of tongue and tactile hallucination occur in cocaine abuse.', 'role': 'assistant'}]