This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
For a patient, of CRF which of the following would be specific indication to sta dialysis? 
Select and explain. 
A. BUN rises to >90 mg/dl, B. Urine output falls to <10 ml/h, C. Hematocrit falls to <30%, D. Pericardial friction rub
D: Pericardial friction rub
Answer: D: Pericardial friction rub 
Explanation: Pericarditis in renal failure (acute or chronic) is an indication to initiate hemodialysis, because untreated uremic pericarditis may progress to pericardial tamponade