This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrine System, Subject name: Physiology
[{'content': 'Which statement about antidiuretic hormone (ADH) is true? \nSelect and explain. \nA. It is synthesized in the posterior pituitary gland, B. It increases salt and water reabsorption in the collecting tubules and ducts, C. It stimulates thirst, D. It has opposite effects on urine and plasma osmolality', 'role': 'user'}, {'content': 'Answer: D \nExplanation: ADH increases the permeability of the collecting tubules and ducts to water, but not to sodium, which in turn increases water reabsorption and decreases water excretion. As a result, urine concentration increases and the retained water dilutes the plasma. ADH is synthesized in the supraoptic and paraventricular nuclei of the hypothalamus and has no direct effect on the thirst center.', 'role': 'assistant'}]