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
Predominant cation of intracellular fluid 
Select and explain. 
A. Na+, B. K+, C. Ca+2, D. H+
B: K+
Answer: B: K+ 
Explanation: K+ concentration in I.C.F is 155 mEq/L of H2O.(Ref: Textbook of physiology AK Jain 5th edition page no.26 table 1.3.3)