This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Haemophilus, Yersinia, Spirochaetes, Ricketssia, Chlamydia, Mycoplasma and Miscellaneous Bacteria), Subject name: Microbiology
[{'content': "The best culture medium for primary isolation of H. influenzae is? \nSelect and explain. \nA. Chocolate agar, B. Fildes' agar, C. Levinthal's medium, D. Nutrient agar", 'role': 'user'}, {'content': "Answer: B \nExplanation: Fildes' agar is made by adding peptic digest of blood to nutrient agar. It gives copious growth of H. influenzae (A.K.A Pfeiffer's bacillus)and it is the best culture medium for the primary isolation of H. influenzae. The other media used for the isolation of H. influenzae are chocolate agar, blood agar, nutrient agar and Levinthal's medium.", 'role': 'assistant'}]