A client is admitted to the emergency department 5 days after an acute coronary syndrome (ACS) troubled by severe fatigue, muscle weakness, and shortness of breath. The client's electrocardiogram (ECG) Indicates sinus tachycardia and the laboratory findings indicate an elevated serum brain natriuretic peptide (BNP) level. Which action is most important for the nurse to implement?

C Provide emotional support. D Auscultate lung fields for fine rales. B Obtain blood for serum cardiac enzymes. A Insert an indwelling urinary catheter.