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: Physiology
ECF volume assessment can be done most accurately by 
Select and explain. 
A. Sucrose, B. Mannitol, C. Inulin, D. Aminopyrine
C: Inulin
Answer: C: Inulin 
Explanation: Indicators used for fluid volumes
1.       Total body water (TBW)- Deuterium Oxide D2O, Tritium oxide, Aminopyrine, Antipyrine
2.       ECF- Inulin, Sucrose, Mannitol, Sodium thiosulphate, Na22
3.       Plasma volume- Evan’s blue, radioactive iodine labelled serum albumin (I125)
 
4.       Blood cell volume- Cr51 labelled RBC
The most accurate indicator for ECF volume assessment is Inulin.