Answer is B (Maintenance) Continuous Renal Replacement Therapy should be initiated during the Maintenance phase (Oliguric Phase) of Acute Renal Failure. Maintenance phase refers to the phase of Renal Failure in which the renal injury becomes established. It is also known as the Oliguric Phase. During this phase the GFR and Urine output progressively decrease until they stabilize at their lowest. Fluid retention gives rise to edema, water intoxication, and pulmonary congestion if the period of oliguria is prolonged. Hypeension frequently develops during this phase. Uremic complications and Electrolyte imbalance typically arise during this phase. Continuous Renal Replacement Therapy (CR) or Dialysis should be initiated in this phase. The oliguric-anuric phase generally lasts 10 to 14 days but can last for several more. The longer the patient remains in this phase, the poorer the prognosis for a return to normal renal function.