The most inferior extent of the peritoneal cavity in the female is the?

The rectouterine and vesicouterine pouches are the two pouches created by draping the peritoneum over the pelvic organs. These pouches are the two lowest extents of the peritoneal cavity, so to answer this question, you just need to decide which one goes lower. Since the uterus is folded over the bladder, the rectouterine pouch can extend to a slightly lower level than the vesicouterine pouch, which makes rectouterine pouch the correct answer. The pararectal fossa is formed by lateral reflections of perineum over the superior one third of the rectum; this space gives the rectum room to fill with feces. The paravesical fossa is a space near the bladder that allows the bladder to expand. Rectovesical pouch is found only found in males, not females! (But, if the question had asked about males, the rectovesical pouch would have been the correct answer.) Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 2. Maternal Anatomy. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.