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
[{'content': 'Which of the following statements about Histamine is true: \nSelect and explain. \nA. Is found in Mast cells, B. Increases gastric acid secretion, C. Related to arousal and blood pressure, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. All Histamine is formed by decarboxylation of amino acid histidineQ, and is found in mast cell, basophils, enterochromaffin like cells of gastric mucosa and brainQ. It has been related to arousal, sexual behaviourQ, regulation of secretion of some anterior pituitary hormones, blood pressure, drinking & pain threshold.', 'role': 'assistant'}]