This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Orthopaedics
[{'content': "The following diseases are associated with HLA B27 and uveitis Except \nSelect and explain. \nA. Bechet's syndrome, B. Reiter's syndrome, C. Psoriasis, D. Ankylosing spondylitis", 'role': 'user'}, {'content': "Answer: A \nExplanation: Features of seronegative spondyloahroahropathiesOnset usually before 40 yearsAbsence of RA factorHLA- B27 positivePresence of uveitisExamples:- ankylosing spondylitis, Reitter's syndrome, Psoriatic ahritis, enteropathic ahritis, Reactive ahritis.(Refer: Mohindra's Fundamentals of Ohopedics, 2nd edition, pg no. 302, 426)", 'role': 'assistant'}]