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
Concentration of sodium in ECF is 
Select and explain. 
A. 130-136 millimoles/lit, B. 132-140 millimoles/lit, C. 138-146 millimoles/lit, D. 140-147 millimoles/lit
C: 138-146 millimoles/lit
Answer: C: 138-146 millimoles/lit 
Explanation: Sodium levels are usually between 136to 145 mmol/L . Blood sodium level less than 136mmol/L mean you have less sodium Ref:Guyton and Hall textbook of medical physiology 12th edition,page number: 50