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: Microbiology
[{'content': '"Giardiasis" is best diagnosed by: \nSelect and explain. \nA. CFT, B. Cyst and trophozite in stool, C. Haemaglutination, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cyst and trophozite in stool', 'role': 'assistant'}]