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: Dental
[{'content': 'Leukotoxin is released by: \nSelect and explain. \nA. P. nucleatum, B. A. naeslundii, C. B. forsythna, D. A. actinomyctem comitans', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]