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
In granuloma, epithelial and giant cells are derived from: 
Select and explain. 
A. T cells, B. B cells, C. Plasma cells, D. Monocyte
D: Monocyte
Answer: D: Monocyte 
Explanation: None