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: Social & Preventive Medicine
[{'content': 'True of 8th Pandemic of Cholera \nSelect and explain. \nA. Originated in 2012, B. Started in Bangladesh, C. Due to O139 El Tor, D. Low attack rate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]