This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
In a healthy individual and a normal diet, which of the following ion is completely absorbed in tubules 
Select and explain. 
A. Na+, B. K+, C. C-, D. HCO3-
D: HCO3-
Answer: D: HCO3- 
Explanation: HCO3- is completely absorbed in renal tubules during normal diet.Ref: Ganong&;s review of medical physiology; 24th edition; page no; 714