This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
Provisional sho antiretroviral regime given in the peripaum period reduces the risk of veical transmission by 
Select and explain. 
A. 35%, B. 50%, C. 65%, D. 75%
B: 50%
Answer: B: 50% 
Explanation: Most transmission of HN occurs during pregnancy and bih, breastfeeding may account for 5-15% of infants becoming infected after delivery Studies have demonstrated that truncated regimens of zidovudine alone or with Lamivudine given to mother during last few weeks of pregnancy or even during labour & delivery & to the infant for a week or less reduced transmission to infant by 50% compared to placebo. rEF : katzung 12 th ed.