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
Confirmatory test for HIV infection is a: 
Select and explain. 
A. ELISA, B. Immunodot, C. RIPA, D. Western Blot
D: Western Blot
Answer: D: Western Blot 
Explanation: None