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: Pharmacology
[{'content': 'Which of the following serotonergic receptors is an autoreceptor ? \nSelect and explain. \nA. 5–HT1A, B. 5–HT1B/1D, C. 5–HT2A, D. 5–HT3', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]