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
[{'content': 'Which of the following is a skeletal muscle relaxant that acts as a central α2 adrenergic agonist : \nSelect and explain. \nA. Tizanidine, B. Brimonidine, C. Chlormezanone, D. Quinine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]