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 of the following statements is true about the epidemiological determinants of measles - \nSelect and explain. \nA. Measles virus survives outside the human body for 5 days, B. Carriers are important sources of infection, C. Secondary attack is less than that of rubella, D. Incidence of measles is more in males than females', 'role': 'user'}, {'content': 'Answer: C \nExplanation: SAR of some important infectious diseases\n\nMeasles\xa0→\xa080%\xa0\nRubella\xa0→\xa090 - 95%\xa0\nChickenpox\xa0→\xa090%\nPertussis\xa0→\xa090%\nMumps\xa0→\xa086%', 'role': 'assistant'}]