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: Social & Preventive Medicine
Index of operational efficiency of Malaria ? 
Select and explain. 
A. API, B. ABER, C. Infant parasite rate, D. Spleen rate
B: ABER
Answer: B: ABER 
Explanation: Ans. is 'b' i.e., ABER Annual blood examination rate (ABER) is an index of operational efficiency.