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: Physiology
[{'content': 'Longest life span among following ? \nSelect and explain. \nA. RBC, B. Plalalets, C. Neutrophils, D. Macrophages', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Macrophages", 'role': 'assistant'}]