This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Labour - III, Subject name: Gynaecology & Obstetrics
[{'content': 'Length of Umbilical cord is \nSelect and explain. \nA. 10-20 cm, B. 20-40 cm, C. 40-70 cm, D. 80-100 cm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Umbilical cord - Normal length- 40-70 cm long- Cord has three vessels : 1 vein(left) and 2 aeries - Length is influenced by amniotic fluid volume and fetal mobility.', 'role': 'assistant'}]