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': 'In all of the following diseases chronic carriers are found except \nSelect and explain. \nA. Gonorrhea, B. Measles, C. Typhoid, D. Hepatitis B', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Chronic carriers: A carrier who excretes bacilli for indefinite periods of time\n– Typhoid – Dysentery\n– Hepatitis B – Cerebrospinal meningitis\n– Malaria – Gonorrhoea\nThere are no carriers in Measles', 'role': 'assistant'}]