Possibe mistake from TPR - Kidney

I believe TPR chose the wrong answer here so just wanted to confimr @aldol16 or anyone else can chime in:

In which region(s) of the nephron is the urine hypertonic compared to plasma?
I. Descending limb of the loop of Henle
II. Upper part of thick ascending limb of the loop
of Henle
III. The collecting duct in the presence of ADH
A. I only
B. II only
C. I and III only
D. I, II, and III

I chose A because the collecting duct is not part of the nephron but the TPR answer...

Possibe mistake from TPR - Kidney