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
Laudanosine is metabolite of which of the following? 
Select and explain. 
A. Cisatracurium, B. Atracurium, C. Pancuronium, D. Gallamine
B: Atracurium
Answer: B: Atracurium 
Explanation: 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.