He has a history of HIV infection for 3 months and he is compliant with his medications

A 23 year old man visits his physician for routine examination. He has a history of HIV infection for 3 months and he is compliant with his medications. He is concerned about developing AIDS.
Which of the following is the most useful test to address his concern?
A-HIV antibody test
B-HIV RT PCR
C-HIV p24 antigen
D-CD4 lymphocyte count
Answer: https://goo.gl/YrZVyQ

Ans B