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: Microbiology
[{'content': 'A patient has undergone a renal transplantation 2 months back and now presented with difficulty in  breathing. X-ray showed bilateral diffuse interstitial pneumonia. The probable etiologic agent would be : \nSelect and explain. \nA. CMV, B. Histoplasma, C. Candida, D. Pneumocystis carinii', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cytomegalovirus (CMV) is the largest virus in the herpes family.\xa0\nIt is transmitted transplacentally from a latent mother to foetus.\xa0\nPostnatal infections are usually acquired by means of sexual intercourse, blood transmission and organ transplantation , clinical disease resembles infectious mononucleosis .\xa0\nIt may cause hepatitis and pneumonitis.\xa0\nFor treatment Ganciclovir is the drug of choice.\n\nRef : textbook of microbiology, C P Baveja, 5th edition , Pg no:446', 'role': 'assistant'}]