This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Forensic Medicine
[{'content': "Magnan's symptom is seen in: \nSelect and explain. \nA. Datura, B. Cocaine, C. Opium, D. Cannabis", 'role': 'user'}, {'content': "Answer: B \nExplanation: Altered tactile sensation: the person feel that some insects are crawling on his skin. This is known asMagnan's symptomorcocaine bugs(formication). Cocaine is an alkaloid derived from plantErythroxylon coca.", 'role': 'assistant'}]