Permeability is the condition of being capable of having materials flow into and out of a membrane. the permeability of a cell membrane is determined by how easily a molecule can diffuse across the membrane. usually, only molecules that are fat-soluble can permeate across a cell membrane. why is this the case?
a. water-soluble molecules are nonpolar.
b. water-soluble molecules are too large.
c. cell membranes are composed of a lipid bilayer.
d. cell membranes are composed of cytosol.

C. Cell membranes are composed of a lipid bilayer.

Explanation:

The cell membrane delimits the contents of the cell. A typical cell membrane is largely made up of phospholipids. Other components include the glycolipids, sterols, and proteins. The phospholipids component arrange themselves in a double layer (bilayer), forming a hydrophobic core.

Fat soluble molecules are able to permeate across the cell membrane due to the lipid bilayer components - lipid in itself being a form of fat.

The correct option is C.

1. is geographic distribution

2 is increasing complexity

3 is transitional forms