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: Surgery
All of the following extraintestinal manifestations of ulcerative colitis respond to colectomy except - 
Select and explain. 
A. Primary sclerosing cholangitis, B. Pyoderma gangrenosum, C. Episcleritis, D. Peripheral arthralgia
A: Primary sclerosing cholangitis
Answer: A: Primary sclerosing cholangitis 
Explanation: None