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': 'Which of the following measurement at pelvic inlet can be assessed directly : \nSelect and explain. \nA. Obstetric conjugate, B. Diagonal conjugate, C. Anatomical conjugate, D. Bisspinous conjugate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Diagonal conjugate', 'role': 'assistant'}]