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
True about endemic typhus 
Select and explain. 
A. Man is the only reservoir of infection, B. Flea is a vector of disease, C. A rash developing into an eschar is characteristics of the disease, D. Culture is diagnostic
B: Flea is a vector of disease
Answer: B: Flea is a vector of disease 
Explanation: None