This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': "'Sensitivity' of a test is - \nSelect and explain. \nA. True negative/ false positive + true negative, B. True positive/ True positive + false negative, C. False positive/ True positive + True negative, D. False negative/ True positive + false negative", 'role': 'user'}, {'content': 'Answer: B \nExplanation: It has been defined as the ability of the test to identify correctly all those who have the disease, true positive. A 90 percent sensitivity means that 90 percent of the diseased screened by the test will give a "true positive " result and the remaining 10 percent a "false negative " result. Ref: 25th edition, Park\'s Textbook of Preventive and Social Medicine, Page no. 152', 'role': 'assistant'}]