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
Which sulphonamide is used for the treatment of ulcerative colitis - 
Select and explain. 
A. Sulphamethiazole, B. Sulphathalazole, C. Sulphaguanidine, D. Salazopyrin
D: Salazopyrin
Answer: D: Salazopyrin 
Explanation: None