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': 'Latent period in primigravida is? \nSelect and explain. \nA. 2 hours, B. 6 to 8 hours, C. 10 to 12 hours, D. 14 to 16 hours', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 6 to 8 hours', 'role': 'assistant'}]