A 49 year old male with an extensive cardiac history presents with 2 hours of crushing chest pain and shortness of breath. He is pale and diaphoretic and tells you that he feels like he is going to die. His medications include nitorglycerin, sildenafil (Viagra) and enalapril (Vasotec). His blood pressure is 140/90mm Hg and his heart rate is 110 beats per min. In addition to administering 100% oxygen, you should:
a. administer one nitro and call medical control
b. place him in a supine position and transport at once
c. obtain physician approval to give the nitroglycerin
d. ask him if he took his Viagra in the past 72 hours