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 a granuloma epithelioid cells are giant cells and derived from 
Select and explain. 
A. T lymphocytes, B. Monocyte-macrophages, C. B lymphocytes, D. Mast cells
B: Monocyte-macrophages
Answer: B: Monocyte-macrophages 
Explanation: None