NIV Has Just Been Initiated on a Patient in Respiratory

NIV has just been initiated on a patient in respiratory distress with an inspiratory positive airway pressure (IPAP) of 12 cm H₂O and an end-expiratory positive airway pressure (EPAP) of 5 cm H₂O.Which of the following would indicate clinical improvement of the patient's condition?
1) Decreased respiratory rate
2) Synchronization with the ventilator
3) Decreased inspiratory muscle activity
4) Decreased arterial oxygen saturation (SₐO₂)

A) 1 and 2 only
B) 1, 2, and 3 only
C) 2, 3, and 4 only
D) 1, 2, 3, and 4