You are answering a USMLE-style medical question. Question: A 79-year-old woman presents to her physician complaining of a persistent non-productive cough and dyspnea after contracting a cold in the past month. She describes herself as being “generally healthy” before the cold started. Medical history includes hypertension and hyperlipidemia. The patient takes hydrochlorothiazide, lisinopril, and atorvastatin. Her parents are both deceased. She does not smoke and only drinks alcohol occasionally. During a review of symptoms, she described a month-long trip to St. Louis, Missouri, to visit family. At the physician’s office, her temperature is 37.0°C (98.6°F), pulse is 82/min, respirations are 20/min, and blood pressure is 130/82 mm Hg. A focused chest exam reveals mild crepitus on the right side. A chest X-ray shows a cavitary lesion in the right lung which is confirmed on chest computed tomography (CT). A lung biopsy is performed to rule out cancer and reveals necrotic granulomatous inflammation with oval yeast in macrophages. Which of the following is the most likely diagnosis? Options: A) Blastomycosis B) Sporotrichosis C) Histoplasmosis D) Onychomycosis Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.