This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid, Electrolyte, Subject name: Pediatrics
[{'content': 'A child has serum osmolality 270 and urine osmolality 1200. What is the most probable diagnosis? \nSelect and explain. \nA. Water deprivation, B. SIADH, C. Central diabetes insipidus, D. Nephrogenic diabetes insipidus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Discussing about the options one by one, Water deprivation Both serum osmolality and urine osmolality increase SIADH Serum osmolality decrease and urine osmolality increases Central diabetes insipidus Serum osmolality increase and urine osmolality decreases in diabetes insipidus (both central and nephrogenic) Nephrogenic diabetes insipidus', 'role': 'assistant'}]