You are answering a USMLE-style medical question. Question: A 62-year-old Caucasian male presents to the emergency room with severe substernal chest pain, diaphoresis, and nausea. Imaging reveals transmural myocardial infarction in the posterior 1/3 of the ventricular septum. Which of this patient's coronary arteries is most likely occluded? Options: A) Left circumflex B) Diagonal perforators C) Septal perforators D) Right main Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.