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
Maximum osmotic gradient is found in ________ 
Select and explain. 
A. Outer cortex, B. Inner medulla, C. Inner cortex, D. Outer medulla
B: Inner medulla
Answer: B: Inner medulla 
Explanation: There is osmotic gradient from cortex to tip of medulla