A 50-year-old woman on ICU is being ventilated with airway pressure release ventilation (APRV). Settings: P-high 28 cmH2O, T-high 4.5 seconds, P-low 0 cmH2O, T-low 0.5 seconds. What is the primary mechanism by which APRV achieves oxygenation?AHigh tidal volumes delivered during the release phaseBSustained high airway pressure (P-high) maintaining alveolar recruitment, with brief releases for CO2 eliminationCHigh respiratory rate from rapid cyclingDInverse I:E ratio ventilation with prolonged expirationENegative pressure ventilation during the T-low phaseCheck my answer