The primary function of the plasma membrane is to act as a selective barrier that regulates the entry and exit of substances into and out of the cell. This includes filtering waste, allowing essential nutrients in, and facilitating communication and recognition between cells. Additionally, in plant cells, the plasma membrane works with the cell wall to help maintain cell shape and structure.
From the options you provided, the most appropriate response regarding the function of the plasma membrane would be:
- It helps recognize other cells.
This emphasizes the membrane's role in cell communication and interaction. However, it should be noted that the plasma membrane also contributes to filtering waste and can be involved in maintaining the shape of plant cells, but its key functions are primarily regulatory and communicative.