Q. A 37-year-old man presents to the medical outpatient department with complaints of persistent cough, wheezing, and shortness of breath for the past three months. He is a non-smoker and has no occupational exposure. On physical examination, the physician noted decreased breath sounds and a bilaterally prolonged expiratory phase. His oxygen saturation is 94% on room air. Spirometry reveals a reduced FEV1/FVC ratio, which improves with bronchodilator use. The rest of the laboratory investigations are normal. What is the most appropriate next step in the management of this patient?