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
Pyoderma-gangrenosum is most commonly associated with - 
Select and explain. 
A. Ulcerative colitis, B. Crohns disease, C. Amoebic colitis, D. Ischemic colitis
A: Ulcerative colitis
Answer: A: Ulcerative colitis 
Explanation: None