This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Physiology
[{'content': 'Half-life of monocytes in circulation is \nSelect and explain. \nA. 6 hrs, B. 12 hrs, C. 24 hrs, D. 1-3 days', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Half life of a monocyte in circulation is one to three days Ref : guyton and hall textbook of medical physiology 12 edition page number:123,124,125', 'role': 'assistant'}]