This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'A patient had undergone a renal transplantation 2 months back and now presented with difficulty breathing. X-ray showed bilateral diffuse interstial pneumonia. The probable etiologic agent would be ? \nSelect and explain. \nA. CMV, B. Histoplasma, C. Candida, D. Pneumocystic carinii', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans is 'a' i.e. CMV CMV is the most common oppounistic infection in a renal transplant (or any organ transplant) patient. It does not generally appear until the end of the first post-transplant month. Infection in the first post-transplant month are most commonly due to conventional nosocomial infections.", 'role': 'assistant'}]