This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'Diganosis of polio - \nSelect and explain. \nA. Detection of polio virus in stool, B. Serology, C. Limb wasting, D. AFP', 'role': 'user'}, {'content': "Answer: A \nExplanation: As fecal excretion may be intermittent ,the best results are obtained by testing fecal samples collected on two seperate days as early in the illness as possible. REF:ANANTHANARAYAN AND PANIKER'S TEXTBOOK OF MICROBIOLOGY 9TH EDITION PAGE NO:487", 'role': 'assistant'}]