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
The tissue macrophages are derived from the 
Select and explain. 
A. Neutrophil, B. Eosinophil, C. Monocyte, D. All of the above
C: Monocyte
Answer: C: Monocyte 
Explanation: None