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: Medicine
Most common site of ulcerative colitis is ? 
Select and explain. 
A. Rectum, B. Caecum, C. Small intestine, D. Appendix
A: Rectum
Answer: A: Rectum 
Explanation: <p>Davidson&;s principles and practice of medicine 22nd edition. *ulcerative colitis invariably involves the rectum and spread proximally in continues manner it involves the entire colon in some cases.</p>