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: Anaesthesia
[{'content': 'Laudanosine is metabolite of which of the following? \nSelect and explain. \nA. Cisatracurium, B. Atracurium, C. Pancuronium, D. Gallamine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Laudanosine is a principal metabolite of atracurium, it has no neuromuscular blocking effects. Laudanosine freely crosses the blood brain barrier and in high concentration act as a CNS stimulant. It is primarily cleared through the liver.', 'role': 'assistant'}]