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 person on a very low potassium diet, which part of the nephron would be expected to reabsorb the most potassium? 
Select and explain. 
A. A, B. B, C. C, D. D
A: A
Answer: A: A 
Explanation: About 65% of the ﬁltered K+ is reabsorbed in the proximal tubule, and another 20% to 30% is  reabsorbed in the loop of Henle. Although most of the daily variation in K+ excretion is caused by  changes in potassium secretion in the distal tubule and CD (collecting duct), only a small percentage of the ﬁltered K+ load can be reabsorbed in these nephron segments.