This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
[{'content': 'One of the following is not a 5-HT receptor antagonist \nSelect and explain. \nA. Ketanserin, B. Lanreotide, C. Methysergide, D. Tropisetron', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 1. Ketanserin It has selective 5-HT2 receptor blocking propey with negligible action on 5-HT1, 5-HT3 and 5 HT4 receptors and no paial agonistic activity. 2. Methysergide is a potent 5-HT2A antagonist, nonselective-acts on S-HT1 receptors. It is used for migraine prophylaxis, carcinoid, and postgastrectomy dumping syndrome. 3. Tropisetron is a 5-HT3 receptor antagonist used mainly as an antiemetic to treat nausea and vomiting following chemotherapy 4. lanreotide is a long-acting analog of somatostatin-used for acromegaly REF: ESSENTIALS OF MEDICAL PHARMACOLOGY; KD TRIPATHI 8TH EDITION', 'role': 'assistant'}]