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': 'Which of the following acts as a neurotransmitter inhibitor: \nSelect and explain. \nA. Glutamate, B. GABA, C. Aspartic acid, D. Lysin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]