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
Co-receptor for R5 variant of HW virus: 
Select and explain. 
A. Integrin, B. CCR 5, C. CXCR 4, D. P 53
B: CCR 5
Answer: B: CCR 5 
Explanation: Ans. b. CCR5