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
[{'content': 'The most impoant source of histamine - \nSelect and explain. \nA. Mast cells, B. Eosinophil, C. Neutrophil, D. Macrophages', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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. .', 'role': 'assistant'}]