This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Labour - normal, abnormal, malposition, malpresentation and their management, Subject name: Gynaecology & Obstetrics
[{'content': 'Pain in early labour is limited to dermatomes- \nSelect and explain. \nA. T11 T12 L1, B. S1 S3, C. L4 L5, D. L2 L3', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Labor pain caused by uterine contractions and cervical dilation is transmitted through visceral afferent sympathetic nerves entering the spinal cord from T10 - L1. Later in labor, perineal stretching transmits painful stimuli through the pudendal nerve and sacral nerves S2 - S4.', 'role': 'assistant'}]