This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
In total flea index true is - 
Select and explain. 
A. Average all Xenopsella cheopis per rat, B. Average number of all fleas of all species per rat, C. Average number of all fleas in a burrow, D. Average number of all fleas in all species of rats to per burrow
B: Average number of all fleas of all species per rat
Answer: B: Average number of all fleas of all species per rat 
Explanation: <p> Total flea index: it is the average number of flea of all species per rat. Reference:Park&;s textbook of preventive and social medicine,K.Park,23rd edition,page no:294 <\p>