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: Microbiology
[{'content': 'Leptospirosis, all are true except \nSelect and explain. \nA. Faeces & urine of rodents is the cause, B. onset of IgM in 2 days, C. Incubation period is 10 days, D. It is sensitive to penicillin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]