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 of the following muscle relaxants causes maximal pain on injection – 
Select and explain. 
A. Succinyl choline, B. Vecuronium, C. Rocuronium, D. Cistracurium
C: Rocuronium
Answer: C: Rocuronium 
Explanation: Pain during injection is an important and common feature of Rocuronium Injection.