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': 'An impoant measure of the communicability of a disease is - \nSelect and explain. \nA. Case fatality rate, B. Disease specific moality rate, C. Infection rate, D. Secondary attack rate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: .secondary attack rate is defined as the number of exposed persons developing the disease within the range of the incubation period following exposure to a primary case.its application is limited only to infectious diseases,in which the primary case is infective,.duration of exposure is also an impoant factor in determining the extent of spread. ref:park&;s textbook,22nd edition,pg no 96', 'role': 'assistant'}]