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
Regarding diameters of normal female pelvis, which of the following is TRUE 
Select and explain. 
A. 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
B: AP Diameter is the shoest diameter at brim
Answer: B: AP Diameter is the shoest diameter at brim 
Explanation: 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