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': 'Which one of the following is not a special incidence rate - \nSelect and explain. \nA. Attack rate, B. Secondary attack rate, C. Hospital admission rate, D. Standardized mortality rate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Special incidence rates \n\nAttack rate (case rate)\nSecondary attack rate\nHospital admission rate', 'role': 'assistant'}]