A client with chronic obstructive pulmonary disease (COPD) reports increased shortness of breath with activity. Which test should the nurse schedule the client for evaluation of the symptoms?

Choice A reason: Spirometry is the gold standard diagnostic test for COPD. It measures airflow limitation, lung volumes, and the degree of obstruction. When a client reports worsening shortness of breath with activity, spirometry provides objective data on pulmonary function and helps evaluate disease progression or response to therapy. Choice B reason: Lung biopsy is not indicated for COPD evaluation. It is typically used to diagnose interstitial lung diseases, malignancies, or unexplained pulmonary pathology. Performing a biopsy in COPD would not provide useful information about airflow limitation. Choice C reason: Antibody testing is used for autoimmune or infectious conditions, not for COPD. COPD is primarily caused by smoking, environmental exposures, and genetic predisposition (such as alpha-1 antitrypsin deficiency), but antibody testing does not evaluate lung function. Choice D reason: Sweat test is used to diagnose cystic fibrosis, not COPD. While both conditions affect the lungs, COPD is an obstructive disease of adulthood, whereas cystic fibrosis is a genetic disorder diagnosed in childhood.