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: Medicine
[{'content': 'What are nitrergic neurous ? \nSelect and explain. \nA. Post ganglionic neurons releasing nitric oxide, B. 1st order neurons releasing nitric oxide, C. Post ganglionic neurons releasing substance P., D. 1st order neurons releasing calcitonin Gene related peptide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer-B. 1st order neurons releasing nitric oxideNitrergic neurons are nerye cells which have neurotransmitter NO.', 'role': 'assistant'}]