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: Pathology
[{'content': 'Most important bactericidal agent is \nSelect and explain. \nA. Cationic basic protein, B. Lactoferrin, C. Lysozyme, D. Reactive O2 species', 'role': 'user'}, {'content': 'Answer: D \nExplanation: H2O2- MPO- halide system is the most efficient bactericidal system of neutrophils', 'role': 'assistant'}]