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: Medicine
[{'content': 'Regarding typhoid ulcer, all of the following are true except: March 2005 \nSelect and explain. \nA. Perforation is common, B. Obstruction results due to stricture formation, C. Bleeding is usual, D. Ileum is the common site', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: Obstruction results due to stricture formation Typhoid ulcers may bleed or perforate, usually during lysis. Most perforations are near the ileocecal valve, measure less than 1 cm across, and lead to peritonitis. These areas become repopulated with lymphoid cells and heal without scarring.', 'role': 'assistant'}]