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': 'Clostridium tetani is - \nSelect and explain. \nA. Gram positive bacilli, B. Gram negative bacilli, C. Gram positive cocci, D. Gram negative cocci', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]