You have been called for a patient with angina. On scene, the 67-year-old man reports that he has a history of angina and the pain started when he was moving firewood from the garage into his house. Unfortunately, the pain has yet to go away, despite three nitroglycerin tablets and 20 minutes of rest. Your next action should be to:

A) Check the patient's vital signs
B) Administer a nitroglycerin tablet and aspirin
C) Attach the AED but do not turn it on
D) Provide supplemental oxygen via nonrebreather

A) Check the patient's vital signs