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': 'True statement regarding "tuberculine test" is - \nSelect and explain. \nA. Used for diagnosis of TB, B. Measures incidence of disease, C. More than 10mm induration in 72 hrs. Indicates positive test, D. Measures immunity status', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The tuberculin test is the only means of estimating the prevalence of infection in a population . Produce a pale wheal of the skin, 6 to 10 mm in diameter. The result of the test is read after48-98 hrs but 72 hrs(3rd day) is the ideal. Reaction exceeding 10 mm are considered positive. Ref:PARK&;S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 23rd edition , Page 185', 'role': 'assistant'}]