This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
[{'content': 'Major neurotransmitter in afferents in nucleus tractus solitarius to regulate cardiovascular system is \nSelect and explain. \nA. Serotonin, B. Glutamine, C. Glycine, D. Norepinephrine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vitamin is the major neurotransmitter in afferents of nucleus tractus solitarius to regulate cardiovascular system Ref: guyton and hall textbook of medical physiology 12 edition page number: 370,371,372', 'role': 'assistant'}]