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
What is p24: 
Select and explain. 
A. Envelope antigen in HIV, B. Core antigen in HIV, C. Genome of HIV, D. Shell antigen
B: Core antigen in HIV
Answer: B: Core antigen in HIV 
Explanation: Ans. b. Core anthigen in HIV