You are answering a USMLE-style medical question. Question: A 45-year-old African-American woman comes to the physician after an episode of hemoptysis. Over the past 8 months, she has had a nonproductive cough, fatigue, and a 9-kg (20-lb) weight loss. She drinks a glass of wine every night and does not smoke. She has a history of hypertension and osteoarthritis. She does not take any medications. She has never traveled out of the country. She works as an accountant. Her temperature is 37.0°C (98.6°F), pulse is 94/min, and blood pressure is 130/90 mm Hg. Lungs are clear to auscultation. An x-ray of the chest shows a 2.5-cm nodule with irregular borders at the apex of the left lung with no mediastinal or hilar enlargement. Which of the following is the most likely diagnosis? Options: A) Carcinoid tumor B) Sarcoidosis C) Squamous cell carcinoma of the lung D) Adenocarcinoma of the lung Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.