Office spirometry performed with an albuterol nebulizer can confirm a diagnosis of asthma because it indicates:

The correct choice highlights that office spirometry performed after administering an albuterol nebulizer can confirm a diagnosis of asthma by demonstrating reversible airway obstruction. In patients with asthma, the airways are hyperreactive, leading to bronchoconstriction and obstruction. When a bronchodilator like albuterol is used, it relaxes the smooth muscles in the airways, resulting in improved airflow and increased lung function as measured by spirometry. A significant improvement in FEV1 (forced expiratory volume in one second) post-nebulization is indicative of reversible obstruction, which is a hallmark of asthma.

In contrast, pulmonary fibrosis, which pertains to scarring and stiffening of the lung tissue, would not typically show significant improvement with bronchodilators, as this condition leads to restrictive rather than obstructive patterns. Chronic carbon dioxide retention is more associated with chronic obstructive pulmonary disease (COPD) and not specifically diagnostic of asthma; significant reversibility in airflow obstruction is not expected in this scenario as they typically experience fixed obstructive patterns. Therefore, demonstrating reversible airway obstruction through spirometry after bronchodilator administration is a key factor in confirming the diagnosis of asthma.