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: Social & Preventive Medicine
[{'content': 'Concentration of sodium in mMol/L in low osmolar ORS is? \nSelect and explain. \nA. 45, B. 90, C. 60, D. 75', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]