This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Lewis triple response is caused due to \nSelect and explain. \nA. Histamine, B. Axon reflex, C. Injury to endothelium, D. Increased permeability', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref Goodman and Gilman 10/e p650 With injection of histamine there is triple response Red spot Wheal Flare', 'role': 'assistant'}]