Pt. came to your clinic and you reveled under medical history he had chronic renal failure , he used to do dialysis the treatment should be.. After one day of dialysis

Pt. came to your clinic and you reveled under medical history he had chronic renal failure , he used to do dialysis the treatment should be?
A. Before one day of dialysis
B. On the day of dialysis
C. After one day of dialysis***
D. After one week of dialysis.