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 is true regarding 5-HT derivatives: March 2009 \nSelect and explain. \nA. Cisapride is selective 5-HT4 antagonist, B. Ondansetron is a 5-HT3 agonist, C. Cyproheptadine is 5-HT2A agonist, D. Sumatriptan action is agonistically 5-HT 1B/1D receptor mediated', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D: Sumatriptan action is agonistically 5-HT 113/1D receptor mediated Cisapride and renzapride are selective 5-HT4 agonists. Ondansetron is a selective 5-HT3 antagonist which inhibits vomiting by blocking these receptors in brainstem as well as in gut wall. Cyproheptadine is 5-HT2A antagonist and has additional H1 antihistaminic, anticholinergic and sedative propeies. Sumatriptan and other triptan are selective 5-HT 113/1D agonists, constricts cerebral blood vessels and has emerged as the most effective treatment of acute migraine attacks.', 'role': 'assistant'}]