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 man, after skinning a dead animal, developed a pustule on his hand. A smear prepared from the lesion showed the presence of Gram positive bacilli in long chains which were positive for McFadyean's reaction. The most likely aetiological agent is- \nSelect and explain. \nA. Clostridium tetani, B. Listeria monocytogenes, C. Bacillus anthracis, D. Actinomyces sp", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]