Anatomy General obstetrics 58d9b048 The smallest diameter of true pelvis is: A Interspinous diameter B Diagonal conjugate C True conjugate D Inteuberous diameter High-Yield Explanation True conjugate - 11cm Diagonal conjugate -12 cm Inteuberus diameter -11cm Interspinous diameter -10 cm Ref: Williams Obs 24e pg 32-33.