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': 'All 5–HT receptors are heptahelical serpentine receptors EXCEPT : \nSelect and explain. \nA. 5–HT1, B. 5–HT2, C. 5–HT3, D. 5–HT4', 'role': 'user'}, {'content': 'Answer: C \nExplanation: All serotonin receptors are G-protein coupled receptors except 5-HT3, which is an anisotropic receptor.', 'role': 'assistant'}]