A

Urine output ≥ 0.5 mL/kg/h is the classic and most dependable end-organ marker that perfusion is adequate after fluid therapy, whereas CVP, pulse, and blood pressure can appear normal despite persistent hypovolemia or vary for non-volume reasons [Czermak et al., 2004, PMID 15103422; Imm & Carlson, 1993, PMID 8490765].