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: Microbiology
Which of the following exposure carries the maximum risk of transmission of HIV? 
Select and explain. 
A. Blood transfusion, B. Sexual intercourse, C. Needle prick, D. Transplacental
A: Blood transfusion
Answer: A: Blood transfusion 
Explanation: HIV:

Maximum risk of transmission: Blood transfusion.
Most common route of transmission: Sexual.