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: Social & Preventive Medicine
Window period for HIV infection is 
Select and explain. 
A. 3-12 weeks, B. 8-20 weeks, C. 6-24 weeks, D. None
A: 3-12 weeks
Answer: A: 3-12 weeks 
Explanation: None