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: Physiology
[{'content': 'The following is inhibitory agent in brain and spinal cord: \nSelect and explain. \nA. Glycine, B. Glutamine, C. Aspaate, D. NO', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Glycine', 'role': 'assistant'}]