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
Which of the following cells are responsible for acid secretion in kidney? 
Select and explain. 
A. I cells, B. P cells, C. Mesangial cells, D. Pericytes
A: I cells
Answer: A: I cells 
Explanation: Intercalated (I cells) are present in late DCT & coical collecting ducts secrete H+ ions and reabsorb K+ ions. Ref: Ganong 25th ed/page 681