[Answered]: A 57-year-old man is referred to the PFT for…

A 57-year-old man is referred to the PFT for increasing SOB. He admits having a chronic cough with a production of think, white sputum, mainly upon awakening. The subject reports that he quit smoking 3 months ago. He averaged approximately two packs of cigarettes per day for 30 years ( 60 pack years) before quitting. His referring physician performed a pulse oximetry in the outpatient clinic and obtained readings of