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': 'One of the epidemiological indices used to measure the tuberculosis problem in a community is the prevalence of infection. Which among the following is widely used to estimate the prevalence of tuberculosis infection in a population? \nSelect and explain. \nA. Sputum smear examination, B. Tuberculin test, C. Chest X-ray, D. Symptoms suggestive of tuberculosis', 'role': 'user'}, {'content': "Answer: B \nExplanation: Prevalence of tuberculosis infection is the percentage of individuals who show a positive reaction to the standard tuberculin test. It represents a cumulative experience of a population to recent and remote infection with Mycobacterium tuberculosis. Ref: Park's Textbook Of Preventive And Social Medicine, By K. Park, 19th Edition, Page 151, 152.", 'role': 'assistant'}]