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 no prophylaxis is given: March 2007 \nSelect and explain. \nA. 25%, B. 50%, C. 75%, D. 100%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: 25% Probability of veical transfer of HIV infection if no prophylactic antiretroviral therapy is given to the mother during pregnancy,labor and delivery and to the newborn ranges from 15-25% in the industrialized countries and from 25-35% in the developing countries.', 'role': 'assistant'}]