This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
[{'content': 'First stage of labour is up to : \nSelect and explain. \nA. Rupture of membranes, B. 3/5 dilatation of cervix, C. Full dilatation of cervix, D. Crowing of head', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Full dilatation of cervix', 'role': 'assistant'}]