This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'Most effective way to prevent HIV veical transmission is \nSelect and explain. \nA. HAA, B. Nevirapine, C. Zidovudine, D. Elective cesarean', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Women enrolled on HAA (Triple ARV prophylaxis) had a much lower (1%) rate of HIV veical transmission as compared to Zidovudine lone HAA showed similar rates of Transmission when Zidovudine monotherapy was combined with single dose of Maternal or neonatal Nevirapine Ref: Perinatal and pediatric HIV/AIDS by Mamatha 1st edition Pgno : 344', 'role': 'assistant'}]