input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A 60-year-old man comes to the physician because of a 2-month history of cough productive of yellow sputum with occasional streaks of blood. He has a history of pulmonary tuberculosis. He is afebrile. Pulmonary examination shows inspiratory crackles at the left infraclavicular area. An x-ray of his chest shows a radiopaque mass in the left upper lung lobe that shifts upon repositioning. A sputum sample does not grow acid-fast bacteria despite multiple cultures. Which of the following is the most likely cause of this patient's condition?   (A) Asbestos inhalation   (B) Neoplastic transformation   (C) Opportunistic colonization   (D) Abscess formation
output: ['(C) Opportunistic colonization <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Asbestos inhalation  (B) Neoplastic transformation  (C) Opportunistic colonization  (D) Abscess formation <> possible answers', "  A 60-year-old man comes to the physician because of a 2-month history of cough productive of yellow sputum with occasional streaks of blood. He has a history of pulmonary tuberculosis. He is afebrile. Pulmonary examination shows inspiratory crackles at the left infraclavicular area. An x-ray of his chest shows a radiopaque mass in the left upper lung lobe that shifts upon repositioning. A sputum sample does not grow acid-fast bacteria despite multiple cultures. Which of the following is the most likely cause of this patient's condition? <> context"]