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
Smooth muscle is not pain sensitive to: 
Select and explain. 
A. Cutting, B. Distension, C. Stretching, D. Torsion
A: Cutting
Answer: A: Cutting 
Explanation: 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.