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
Cheopis Index used for 
Select and explain. 
A. Rabies, B. Plague, C. Yellow fever, D. Leishmaniasis
B: Plague
Answer: B: Plague 
Explanation: Flea indices Flea indices are useful measurements of the density of fleas. they are also useful in evaluating the effectiveness of a spraying programme.The following flea indices are widely used in rat flea surveysTotal flea indexCheopis indexSpecific percentage of fleasBurrow indexRef: Park; 23rd ed; Pg.no: 294