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: Medicine
[{'content': 'Chest X-ray revealed bilateral, symmetrical interstitial infiltrates in a 30-year old HIV positive patient who presented with fever, dyspnoea, non-productive cough, and cyanosis. The MOST likely diagnosis is: \nSelect and explain. \nA. Tuberculosis, B. Cryptococcosis, C. Pneunocystis carinii pneumonia, D. Toxoplasmosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Chest X-ray findings of bilateral, symmetrical interstitial infiltrates in a HIV positive patient with respiratory symptom is almost diagnostic of Pneunocystis carinii pneumonia. Ref: Harrisons principles of internal medicine 18th edition, chapter 189.', 'role': 'assistant'}]