The circulatory aids with the immune system because they provide white-blood cells to help fight with the diseases or sicknesses.
Plasmolysis is the reason. The reason that the Elodea cell prevents from collapsing completely is that the Plasmolysis is the main reason because it always has water to keep it full. The answer in this question is Plasmolysis is the reason because it always has water to keep it full.
I believe it's B. Apologies if I'm wrong.
Answer:
I believe the answer is a single bacteria cell.