A good model of the cell membrane would be
A. a chain link fence.
B. a film of food wrap.
C. a wall of stones and mortar.
D. a river with objects floating in it.

C. A wall of stones and mortar

This would act as a model describing the cell membrane.

Explanation;

A cell membrane is made up of a phospholipid bilayer with embedded proteins.

A cell membrane hold the different components of the cell together and to protect it from the environment outside the cell. It acts as a boundary between the inside environment and the outside environment of a cell.

It regulates the materials that enters and exits the cell; through selective movement of substances in and out of the cell.