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
Isotonic urine is formed at the level of 
Select and explain. 
A. PCT, B. DCT, C. Ascending loop of henle, D. Descending loop of henle
B: DCT
Answer: B: DCT 
Explanation: PCT ⇒ Isotonic urine
Decending loop of hanle ⇒ Hypertonic urine
DCT ⇒ Hypotonic urine.