This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
The most impoant source of histamine - 
Select and explain. 
A. Mast cells, B. Eosinophil, C. Neutrophil, D. Macrophages
A: Mast cells
Answer: A: Mast cells 
Explanation: Harshmohan textbook of pathology 7th edition. histamine: is a vaso active amine stored in the granules of mast cells, basophils and platelets. Histamine is released from the cell by various stimuli. .