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: Physiology
[{'content': 'During Flight or Fight reaction, which of the following is responsible for increase in local blood flow \nSelect and explain. \nA. Sympathetic system mediated cholinergic release, B. Local hormones, C. Para-sympthetic cholinergic, D. Endocrine factors only', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Main actions of sympathetic system, when activated, are mediated through noradrenaline. But the local blood flow is increased due to release of acetylcholine at sympathetic cholinergic endings.', 'role': 'assistant'}]