The Patient Is Being Admitted to the Emergency Department with Complaints

The patient is being admitted to the emergency department with complaints of shortness of breath.The patient has had chronic lung disease for many years but still smokes.The nurse should

A) Administer high levels of oxygen.
B) Use oxygen cautiously in this patient.
C) Place a paper bag over the patient's face to allow rebreathing of carbon dioxide.
D) Administer CO₂ via mask.