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
In a healthy individual on a normal diet, which of the following ion is completely absorbed in tubules 
Select and explain. 
A. Na+, B. K+, C. Cl-, D. HCO3-
D: HCO3-
Answer: D: HCO3- 
Explanation: Total reabsorption in tubules
Glucose- 100%
Amino acids- 100%
HCO3-- 100%
Na+- 99.4%
K+- 93.3%
Cl-- 99.2%