In order for a reverse-osmosis freshwater generator to be able to overcome the osmotic pressure without damaging the spiral-wound membrane modules, the pressure must be controlled. What is the location of the pressure regulator?

Correct Answer: Option B — Brine outlet from the membrane modules.

The brine back pressure regulator is installed on the brine discharge line to maintain the required operating pressure across the membrane modules. By restricting the flow of the concentrated brine, it ensures the system maintains sufficient pressure to overcome the natural osmotic pressure of the seawater feed.