You are answering a USMLE-style medical question. Question: A 52-year-old man with hypertension and hyperlipidemia comes to the emergency department 30 minutes after the sudden onset of substernal chest pain while sitting in a chair at home. He reports drinking 2 glasses of whiskey earlier that day, after a stressful day at work. Current medications include hydrochlorothiazide and atorvastatin. He has smoked one pack of cigarettes daily for the past 20 years. His pulse is 102/min, and blood pressure is 135/88 mm Hg. Cardiopulmonary examination shows normal heart sounds. An ECG obtained on arrival at the emergency department shows ST-segment elevations in the anterior leads. 15 minutes later, the patient's chest pain has resolved and a repeat ECG shows no abnormalities. Which of the following is the most likely underlying mechanism of this patient’s chest pain? Options: A) Coronary artery vasospasm B) Coronary artery vasodilation C) Atherosclerotic plaque rupture D) Pericardial inflammation Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.