This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Malaria, Subject name: Social & Preventive Medicine
In a town with population of 100,000, the number of slides examined is 5000. Out of these, 100 slides were positive for malaria. The API is? 
Select and explain. 
A. 2, B. 5, C. 1, D. 0.5
C: 1
Answer: C: 1 
Explanation: ANSWER: (C) 1REF: Park 20th edition page 227API= (confirmed cases/population) x 1000: it is a measure of malaria incidence.= 100/100000 x 1000 = 1ABER= (slides examined/population) x 100: It is a measure of operational efficiency. ABER for this case=5