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
HIV affects -a) Only T helper cellsb) T helper and macrophagesc) NK cellsd) B - lymphocytes 
Select and explain. 
A. c, B. bd, C. ab, D. ac
B: bd
Answer: B: bd 
Explanation: None