This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
All of the following are used to measure ECF volume, except 
Select and explain. 
A. Sucrose, B. Sodium chloride, C. Inulin, D. Heavy water
B: Sodium chloride
Answer: B: Sodium chloride 
Explanation: ECF is measured using inulin which is a polysaccharide. Other substances used are mannitol and sucrose. These substances cannot enter a cell but can freely cross the capillary membrane and thus distribute evenly in the ECF compaments. (REF: TEXTBOOK OF MEDICAL PHYSIOLOGY GEETHA N 2 EDITION, PAGE NO - 61)