This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Leprosy, HIV & STDs, Subject name: Social & Preventive Medicine
[{'content': 'Most common oppounistic infection in AIDS worldwide is:- \nSelect and explain. \nA. Tuberculosis, B. Candida, C. Histoplasmosis, D. Pneumocystis carinii pneumonia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: AIDS:- - Caused by HIV . - Mode of transmission - Sexual, blood, needle/syringes, veical. - Prevalence - 0.22%. - MC age group affected - 30-44yrs. - MC oppounistic infection in AIDS:- World : Pneumocystis carinii pneumonia. India: Tuberculosis.', 'role': 'assistant'}]