<prompt> Engagement of fetal head is with reference to:Biparietal diameterBitemporal diameterOccipitofrontal diameterSuboccipitofrontal diameter  <response>: Ans. is a, i.e. Biparietal diameterEngagement is said to occur when the largest transverse diameter of fetal head crosses the pelvic inlet.Largest transverse diameter of fetal head is: Biparietal diameter. 