This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Body composition and Acid base Balance, Subject name: Pediatrics
[{'content': 'Calculate the plasma osmolality if serum Na+ is 130, glucose is 180 mg/dl, & BUN is 56, K+ is 5, cl- is 117. \nSelect and explain. \nA. 260, B. 270, C. 280, D. 290', 'role': 'user'}, {'content': 'Answer: D \nExplanation: * Normal plasma osmolality = 285 - 295 mosm/kg *', 'role': 'assistant'}]