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
The Principal site of acidification of urine is : 
Select and explain. 
A. Distal convoluted tubule, B. Proximal convoluted tubule, C. Loop of Henle, D. Collecting duct
D: Collecting duct
Answer: D: Collecting duct 
Explanation: D i.e.Collecting ductAcidification of tubular fluid occurs in distal nephron, paicularly the collecting duct, (CD).