This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of Health and Disease, Subject name: Social & Preventive Medicine
[{'content': 'Killing power of disease is \nSelect and explain. \nA. Secondary attack rate, B. Case fatality rate, C. IMR, D. MMR', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. b (Case fatality rate). (Ref. Park, PSM, 17th ed., 52, 88)- CFR is measurement of killing power of a disease.Secondary attack rate =Number of exposed persons developing the disease within the range of IP------------------------------------------Total number of exposed/"susceptible" contactsx 100- The primary case is excluded from both the numerator and denominator.', 'role': 'assistant'}]