This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
[{'content': 'Largest pathogenic Bacillus organism is - \nSelect and explain. \nA. Bacillum subtilis, B. Bacillum cereus, C. Bacillum anthrocis, D. Bacillum megaterism', 'role': 'user'}, {'content': "Answer: C \nExplanation: The anthrax bacillus is one of the largest of pathogenic bacteria measuring 3-10 x 1-16 um. It resembles a Bamboo stick appearance Ref: Ananthanarayan & paniker's Textbook of Microbiology 9th edition pg no 244", 'role': 'assistant'}]