This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'True about maximum isolation period of enteric fever is - \nSelect and explain. \nA. Up to 3 days after staing the treatment, B. Till 3 consequent negative stool cultures are obtained from the patient, C. Till the fever subsides, D. Till Widal test becomes negative', 'role': 'user'}, {'content': "Answer: B \nExplanation: Man is the only known reservoir of infection., viz cases, and carriers. A case is infectious as long as bacilli appear in urine or stools Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 258, 259", 'role': 'assistant'}]