A client with a history of unstable angina presents to the emergency department with constant chest pressure that is unrelieved with rest. The client appears anxious, pale, and diaphoretic. After obtaining the client's vital signs, which action should the nurse take next?

A. Evaluating upper and lower extremities for perfusion, pulse volume, and pitting edema is important in assessing peripheral perfusion, but the priority action in this scenario is to initiate treatment for a suspected myocardial infarction. B. Placing an indwelling urinary catheter and instituting strict intake and output measurements is not the priority action in this scenario. The client's symptoms and history suggest a cardiac event requiring immediate intervention. C. Administering four 81 mg aspirin tablets (324 mg total) as soon as possible is the priority action for a client presenting with chest pain suggestive of acute coronary syndrome. Aspirin helps to prevent platelet aggregation and reduce the risk of clot formation. D. Securing client consent for coronary angiography and percutaneous coronary intervention may be necessary but is not the immediate priority. The client needs immediate treatment to alleviate symptoms and stabilize the condition.