Final answer:
Immediate treatment for MI includes administering supplemental oxygen, aspirin, and nitroglycerin to improve blood flow to the heart and relieve symptoms.
Step-by-step explanation:
Immediate treatments for MI (myocardial infarction) include administering supplemental oxygen, aspirin that helps to break up clots, and nitroglycerin administered sublingually to facilitate its absorption. These treatments aim to relieve the symptoms and improve blood flow to the heart. In this case, since the patient's chest pain is similar to a previous heart attack and oxygen has not provided relief, the most appropriate treatment would be nitroglycerin (B).