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': 'Engagement in primigravida occurs at : \nSelect and explain. \nA. Beginning of labour, B. 36 weeks, C. 34 weeks, D. Second stage of labour', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Beginning of labour', 'role': 'assistant'}]