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
What is the major source for histamine released during inflammation? 
Select and explain. 
A. Platelets, B. Mast cells, C. Basophils, D. Endothelial cells
B: Mast cells
Answer: B: Mast cells 
Explanation: Mast cells are the richest source of histamine