<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 57-year-old woman comes to the physician because of several years of recurrent pelvic pain and constipation. She has increased fecal urgency and a sensation of incomplete evacuation following defecation. She has had no problems associated with urination. Her last menstrual period was 6 years ago. She has had three uncomplicated vaginal deliveries. Physical examination shows normal external genitalia. Speculum examination of the vagina and the cervix shows bulging of the posterior vaginal wall during Valsalva maneuver. Weakness of which of the following structures is the most likely cause of this patients symptoms?? A: Pubocervical fascia, B: Rectovaginal fascia, C: Uterosacral ligament, D: Cardinal ligament, E: Bulbospongiosus muscle,  <response>: This is a clinical vignette describing a 57-year-old woman with symptoms of pelvic pain, constipation, fecal urgency, and sensation of incomplete evacuation. She has a history of 3 uncomplicated vaginal deliveries. On exam, she has posterior vaginal wall prolapse during Valsalva. The question asks to identify the weakened pelvic support structure that is most likely causing her symptoms.Choices include:A Pubocervical fascia - incorrect, supports anterior vaginal wall B Rectovaginal fascia - correct, supports posterior vaginal wallC Uterosacral ligament - incorrect, supports cervixD Cardinal ligament - incorrect, lateral support of uterusE Bulbospongiosus muscle - incorrect, not a pelvic support structureB: Rectovaginal fascia 