Which term refers to spaces between body membranes that have the potential to separate?

The term that refers to spaces between body membranes that have the potential to separate is indeed the correct choice. Potential spaces are anatomical areas that, under normal conditions, may appear to be adjacent or connected but can become distended or separated under certain circumstances, such as the accumulation of fluid or other pathological processes.

For example, the pleural cavity in the thoracic region is a potential space between the visceral and parietal pleura. Under normal circumstances, these layers are in close proximity to facilitate the mechanics of breathing, but they can separate if fluid accumulates due to injury or disease.

The other terms do not accurately describe this concept. Serosa refers to membrane surfaces that line the closed cavities of the body and cover the organs within these cavities; it is not specifically about the separation potential. Intraperitoneal pertains to structures that are located within the peritoneal cavity, which is a specific location rather than a general descriptor of spaces between membranes. Retroperitoneal describes organs that are situated behind the peritoneum, away from the potential space in the abdominal cavity. Thus, these terms do not convey the idea of spaces that can separate or enlarge when necessary.