This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuromuscular Blocker, Subject name: Anaesthesia
Fastest acting nondepolarizing neuromuscular blocker- 
Select and explain. 
A. Rocuronium, B. Pancuronium, C. Succinylcholine, D. Mivacurium
A: Rocuronium
Answer: A: Rocuronium 
Explanation: Rocuronium has onset of action at 1mg/kg 90 seconds Rocuroniumis the muscle relaxant of choice for day-care surgery. intermediate-acting muscle relaxant with a rapid onset (90 s). Rapacuronium has onset of action 75 secs but it is not in clinical use. Rest all nondepolarising neuromuscular blocker has onset of action - 3-5 minutes