This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal System, Subject name: Physiology
Net secretion of K+ occurs in the:- 
Select and explain. 
A. Duodenum, B. Jejunum, C. Ileum, D. Colon
D: Colon
Answer: D: Colon 
Explanation: Small intestine Colon Reabsorption of Na+, Cl-, K+, watersecretion of HCO-3 Reabsorption of Na+, Cl-, water secretion of K+, HCO-3