A nurse is caring for a client who has COPD and is receiving oxygen at 2 L/min via nasal cannula. The client tells the nurse she has been having difficulty breathing. Which of the following actions is the nurse's priority at this time?

A. Increase the oxygen flow to 3 L/min: Adjusting oxygen flow should follow a focused assessment and, unless ordered or indicated by assessment findings, should not be the first action. B. Assess the client's respiratory status: Rapid assessment (rate, effort, lung sounds, SpO₂) is the priority to determine the cause of increased dyspnea and guide appropriate interventions. C. Have the client cough and expectorate secretions: Encouraging coughing may help if secretions are the issue, but this should follow an assessment that identifies secretion retention as the problem. D. Instruct the client to use a pursed-lip breathing technique: Pursed-lip breathing can assist ventilation for COPD patients, but it is appropriate after assessing whether the client can follow and benefit from the technique.