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: Pathology
Which of the following is a polygenic disorder 
Select and explain. 
A. Ankylosing spondylitis, B. Huntington's disease, C. Fragile X syndrome, D. Pendred syndrome
A: Ankylosing spondylitis
Answer: A: Ankylosing spondylitis 
Explanation: . Ankylosing spondylitis