The Respiratory Therapist Is Treating a Hypoxemic Child with a Nasal

The respiratory therapist is treating a hypoxemic child with a nasal cannula at 3 L/min.However,after few hours the child becomes tachypneic,demonstrates shallow breathing,and becomes hypoxemic.What should the therapist do at this time?

A) Increase flow rate on the cannula to 4 L/min.
B) Switch to a partial rebreathing mask.
C) Switch to an air-entrainment mask.
D) Apply positive pressure ventilation.