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 of potassium in reduced osmolarity ORS (mmol/litre) ? 
Select and explain. 
A. 75, B. 65, C. 20, D. 10
C: 20
Answer: C: 20 
Explanation: Ans. is 'c' i.e., 20