Mr. Jackson also reports dull, aching pain from his left shoulder radiating to his left arm. He states the pain comes and goes, and he rates the pain as 5 on a pain scale of 0 to 10. The RN applies electrodes from the ECG machine to obtain a tracing of Mr. Jackson's heart function and then analyzes Mr. Jackson's ECG strip, which shows a normal sinus rhythm.

Which prescription should the RN plan to implement first for Mr. Jackson?

A) Administer pain medication
B) Order a chest X-ray
C) Initiate thrombolytic therapy
D) Consult a cardiologist