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': '____________ is an example for rapidly acting\nneurotransmitter \nSelect and explain. \nA. Somatostatin, B. Calcitonin, C. Substance P, D. Glycine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]