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': 'Possibility of veical transfer of HIV infection if prophylaxis is given: March 2007 \nSelect and explain. \nA. 1%, B. 2%, C. 3%, D. 4%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: 1% Possibility of veical transfer of HIV infection in pregnant woman who are receiving combination antiretroviral therapy is approaching 1%.', 'role': 'assistant'}]