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': 'Most common source of Diphtheria \nSelect and explain. \nA. Case, B. Carrier, C. Both, D. None', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Carrier Diphtheria is an acute infectious disease caused by toxigenic strains of corynebacterium diphtheriae. Source of infection cases or carriers; carriers are common sources of infection, their ratio is estimated to be 95 carriers for 5 clinical cases. Infective period - 14 - 28 days from the onset of disease. Age group - 1 to 5 years Sex - Both sexes Incubation period - 2 - 6 days", 'role': 'assistant'}]