This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET 2019, Subject name: Surgery
[{'content': 'Flask shaped ulcers in colon is caused by:- \nSelect and explain. \nA. Giardia lamblia, B. Entamoeba histolytica, C. H. Pylori, D. Enterobius vermicularis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Amoebiasis: M/C pathogenic amoeba in humans - E. histolytica Trophozoites of E. histolytica attaches to submucosa of cecum & ascending Colon to produce "FLASK SHAPED ULCERS" and causes abscess.', 'role': 'assistant'}]