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
Possibility of veical transfer of HIV infection if no prophylaxis is given: March 2007 
Select and explain. 
A. 25%, B. 50%, C. 75%, D. 100%
A: 25%
Answer: A: 25% 
Explanation: 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.