This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
[{'content': "Primary sclerosing cholangitis is associated with \nSelect and explain. \nA. Ulcerative cholangitis, B. Retroperitoneal fibrosis, C. Reidel's thyroiditis, D. All of the above", 'role': 'user'}, {'content': "Answer: D \nExplanation: Features of ulcerative colitis in case of PSC(70%).PSC may be associated with retroperitoneal fibrosis,mediastinal fibrosis,Riedel's thyroiditis,orbital pseudotumour. Reference:SRB's manual of surgery,5th edition,page no:658.", 'role': 'assistant'}]