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': 'Vasopressin is secreted by: \nSelect and explain. \nA. Supraoptic  nucleus, B. Preoptic nucleus, C. Paraventricular nucleus, D. Posterior nucleus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ADH (vasopressin) is secreted by supraoptic nucleus.\nOxytocin is secreted by\xa0paraventricular nucleus.', 'role': 'assistant'}]