This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Smooth Muscle, Subject name: Physiology
[{'content': 'Smooth muscle is not pain sensitive to: \nSelect and explain. \nA. Cutting, B. Distension, C. Stretching, D. Torsion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Smooth muscle is not sensitive to cutting type of pain. E.g. The intestinal smooth muscle. The reason is - It is sparsely innervated by A-delta type of nerve fibers that carry fast pain.', 'role': 'assistant'}]