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
Leptospirosis, all are true except 
Select and explain. 
A. 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
B: onset of IgM in 2 days
Answer: B: onset of IgM in 2 days 
Explanation: None