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
Which muscle relaxant has Maximum duration of action? 
Select and explain. 
A. Atracurium, B. Vecuronium, C. Rocuronium, D. Doxacurium
D: Doxacurium
Answer: D: Doxacurium 
Explanation: Ans. is 'd' i.e., Doxacurium