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: Pharmacology
Which of the following is a muscle relaxant 
Select and explain. 
A. Scoline, B. Pentazocine, C. Hyoscin, D. Phenylephrine
A: Scoline
Answer: A: Scoline 
Explanation: None