This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
Concentration of sodium in mOsm/l in low osmolar ORS is? 
Select and explain. 
A. 45, B. 75, C. 90, D. 60
B: 75
Answer: B: 75 
Explanation: Concentration of sodium in low osmolar ORS is 75 mOsm/l Osmolarity reduced to avoid possible adverse effects of hypeonicity on net fluid absorption by reducing the concentration of glucose and sodium chloride in the solution . Ref: PARK&;S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 23rd edition pg 224