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: Medicine
Which of the following condition is associated with Restless leg syndrome (RLS)? 
Select and explain. 
A. Hyperkalemia, B. Hypercalcemia, C. Hyperphosphatemia, D. Chronic renal failure
D: Chronic renal failure
Answer: D: Chronic renal failure 
Explanation: Chronic renal failure