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
[{'content': 'In a community with one lakh population , 20,000 slides were examined in a paicular year. Out of these, 100 were positive for malarial parasite. What is the Annual Parasite Incidence (API) in this community ? \nSelect and explain. \nA. 5, B. 2, C. 1, D. 0.5', 'role': 'user'}, {'content': 'Answer: C \nExplanation: <p> Annual parasite incidence(API)= (Confirmed cases during one year/population under surveillance)*1000. Here,API=(100/100000)*1000 =1. Reference:Park&;s textbook of preventive and social medicine,K.Park,23rd edition,page no:261. <\\p>', 'role': 'assistant'}]