<prompt> Single pelvic ala is present in:Roberts pelvisNaegele s pelvisOsteomalacia pelvisRickets pelvis  <response>: Ans. B. Naegeles pelvisNaegeles pelvis - Ala on one side is absenta. Roberts pelvis - Ala on both sides are absentb. Osteomalacic pelvis - the shape of inlet is triradiatec. Rachitic pelvis - shape of inlet is reniformd. The expected date of delivery can be calculated by Naegeles rule 