This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'Regarding diameters of normal female pelvis, which of the following is TRUE \nSelect and explain. \nA. Oblique diameter is the largest diameter of inlet, B. AP Diameter is the shoest diameter at brim, C. Obstetric conjugate indicates status of mid pelvis, D. Obstetric conjugate is calculated by adding 1.5 cm to diagonal conjugate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: There is reason to suspect midpelvic contraction whenever the interspinous diameter is less than 10 cm. If the diameter is 8 cm or lesser, then its Diagnosed mid pelvic contraction', 'role': 'assistant'}]