Why is the use of positive end-expiratory pressure

Why is the use of positive end-expiratory pressure (PEEP) beneficial when treating mechanically ventilated patient with pneumonia and acute respiratory distress syndrome (ARDS)?

Group of answer choices

PEEP increases alveolar recruitment.

PEEP decreases capillary leakage.

PEEP increases dead-space ventilation.

PEEP decreases intrapulmonary shunt.