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 salmonolosis disease, isolation is done till \nSelect and explain. \nA. Fever subsides, B. Blood culture negative, C. Stool culture negative for three times, D. Spleen subsides', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]