This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid and electrolytes, Subject name: Pediatrics
Osmolarity of standard ORS solutions is ? 
Select and explain. 
A. 245, B. 311, C. 330, D. 210
B: 311
Answer: B: 311 
Explanation: Osmolarity of standard ORS solution is 245 mmol/l Reference: Ghai pediatrics eighth edition pg no 294