This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Haemophilus, Yersinia, Spirochaetes, Ricketssia, Chlamydia, Mycoplasma and Miscellaneous Bacteria), Subject name: Microbiology
Vector for plague is- 
Select and explain. 
A. Pediculus humanus, B. Xenopsylla cheopis, C. Ixodid daminii, D. Haemaphysalis spinigera
B: Xenopsylla cheopis
Answer: B: Xenopsylla cheopis 
Explanation: Option 2 Xenopsylla cheopis It is the agent of plague, a zoonosis, transmitted from rodents by rat flea. The natural reservoir for plague is rodents. Option 1 Vector- Louse (Pediculus humanus corporis) cause:- Trench fever Option 3 Ixodid daminii: causative agent of Lyme's disease Option 4 Haemaphysalis spinigera: causative agent of KFD