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
All of the following are used for measurement of ECF volume except 
Select and explain. 
A. Antipyrine, B. Inulin, C. Mannitol, D. Sodium Thiocyanate
A: Antipyrine
Answer: A: Antipyrine 
Explanation: Antipyrine is used for measurement of total body water.