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': "A child presents with fever and Lymphadenopathy. On examination a grey membrane can be seen over Left tonsil. Which of the following media is used for definitive diagnosis of organism? \nSelect and explain. \nA. Loffler's serum slope, B. Potassium tellurite agar, C. Chocolate agar, D. Tinsdale agar", 'role': 'user'}, {'content': "Answer: B \nExplanation: For early diagnosis of C.diphtheria - Loffler's serum slope\nFor defenitive diagnosis - Potassium tellurite agar.", 'role': 'assistant'}]