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: Pediatrics
What is the amount of trisodium citrate dihydrate in WHO ORS ? 
Select and explain. 
A. 1.5 gm, B. 2.5 gm, C. 2.9 gm, D. 3.9 gm
C: 2.9 gm
Answer: C: 2.9 gm 
Explanation: None