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': 'The distance from the upper end of sacrum to lower border of pubis corresponds to: March 2009 \nSelect and explain. \nA. Transverse conjugate, B. True conjugate, C. Diagonal conjugate, D. Obstetric conjugate', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Diagonal conjugate', 'role': 'assistant'}]