This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
[{'content': 'Medusa head colonies on nutrient agar is seen in - \nSelect and explain. \nA. Pneumococcus, B. Legionella, C. Brucella, D. Anthrax', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Anthrax * Important characteristics of B. anthracis : 'Inverted fir tree' appearance, 'frosted glass' appearance, medusahead colony, string of pearl's reaction, M' Fadyean's reaction.", 'role': 'assistant'}]