This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Anatomy
[{'content': 'Pain in early labor is limited to dermatomes \nSelect and explain. \nA. T10 - L1, B. S1- S3, C. L4- L5, D. L2- L3', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In early stages of labor pain is mainly uterine in origin . Distributed along the cutaneous nerve distribution T10 - L1 In later stages pain is due to dilatation of cervix referred to back through sacral plexus', 'role': 'assistant'}]