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: Medicine
Which of the following HLA is specific to rheumatoid arthritis - 
Select and explain. 
A. HLADRI, B. HLADR2, C. HLADR3, D. HLADR4
D: HLADR4
Answer: D: HLADR4 
Explanation: None