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': 'Leukotrienes are secreted by all except \nSelect and explain. \nA. Macrophages, B. T4 cells, C. T8 cells, D. Platelets', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Platelets", 'role': 'assistant'}]