You are answering a USMLE-style medical question. Question: A 78-year-old man is brought to the emergency department because of a 1-day history of painful enlarging bruises and skin ulceration over his thighs and external genitalia. He has type 2 diabetes mellitus, mitral regurgitation, and atrial fibrillation. Three days ago, he was started on treatment with warfarin. His only other medications are metformin and lisinopril. His temperature is 37.8°C (100.0°F), pulse is 108/min and irregularly irregular, and blood pressure is 155/89 mm Hg. Examination of the skin shows large purpura, hemorrhagic bullae, and areas of skin necrosis over his anterior legs, gluteal region, and penis. This patient is most likely to benefit from treatment with which of the following? Options: A) Hyperbaric oxygen B) Protein C concentrate C) Argatroban D) Tranexamic acid Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.