Pediatrics A child has serum osmolality 270 and urine osmolality 1200. What is the most probable diagnosis? A Water deprivation B SIADH C Central diabetes insipidus D Nephrogenic diabetes insipidus 💡 Explanation A child has serum osmolality 270 and urine osmolality 1200. What is the most probable diagnosis? ✓ Correct Answer: B. SIADH