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
HLA B27 is associated with all except-a) Ankylosing spondylitisb) Pernicious anemiac) Behcet's syndromed) Reiter's sydrome 
Select and explain. 
A. a, B. c, C. bc, D. ad
C: bc
Answer: C: bc 
Explanation: None