This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Muscle relaxants, Subject name: Anaesthesia
Which neuromuscular blocker releases histamine 
Select and explain. 
A. Pancuronium, B. Atracurium, C. Vecuronium, D. Rocuronium
B: Atracurium
Answer: B: Atracurium 
Explanation: Atracurium * Bisquaternary ammonium Benzylisoquinoline * ED 95 = 0.2 to 0.25mg/kg * Intubating dose- 0.5mg/kg. * Maintenance - 0.05 to 0.1mg/kg Drug of choice in patient with renal and hepaticd dysfunction * onset of action= 3-5min (0.5mg/kg) * duration of action= 20-35min * about 82% is bound to albumin * triggers dose-dependent histamine release that becomes significant at doses above 0.5 mg/kg