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
[{'content': 'A population of 100000 is under surveillance during an year. 100 cases were positive for malarial thick smear. What is the annual parasite index ? \nSelect and explain. \nA. 1 per 1000, B. 2 per 1000, C. 10 per 1000, D. 20 per 1000', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e.,1 per 1000 Annual Parasite Incidence =(confirmed cases during one year/population under surveillancee) x 1000Population under surveillance = 100000Confirmed cases = 100 100API - x 1000 = 1 100,000So, API is 1 per 1000 population.", 'role': 'assistant'}]