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 synthesized in the: \nSelect and explain. \nA. Anterior pituitary, B. Hypothalamus, C. Juxtaglomerular apparatus, D. Vasomotor centre', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vasopressin.\nVasopressin,\xa0also\xa0called\xa0antidiuretic\xa0hormone,\xa0is\xa0even\xa0more\xa0powerful\xa0than\xa0angiotensin\xa0II\xa0as\xa0a vasoconstrictor,\xa0thus\xa0making\xa0it\xa0one\xa0of\xa0the\xa0body’s\xa0most potent\xa0vascular\xa0constrictor\xa0substances.\xa0It\xa0is\xa0formed\xa0in nerve cells in the hypothalamus of the brain but is then transported downward by nerve axons to the posterior pituitary gland, where it is finally secreted into the blood.\nReference: GUYTON AND HALL TEXTBOOK OF MEDICAL PHYSIOLOGY, THIRTEENTH EDITION(INTERNATIONAL EDITION ) page no 1014', 'role': 'assistant'}]