This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Grade I lymphedema means 
Select and explain. 
A. Pitting edema upto the ankle, B. Pitting edema upto the knee, C. Non pitting edema, D. Edema disappearing after overnight rest
D: Edema disappearing after overnight rest
Answer: D: Edema disappearing after overnight rest 
Explanation: .