Cell Membranes Have Distinct Inside and Outside Faces

Multiple Choice

Cell membranes have distinct inside and outside faces. Which of the following statements is the most plausible explanation for the asymmetrical nature of the two layers of the membrane?

A) Cell membranes form a border between adjacent cells in tightly packed tissues such as epithelium.
B) Cell membranes communicate signals between different cell types.
C) The two layers of a cell membrane face different environments and carry out different functions.
D) Proteins only function on the cytoplasmic side of the cell membrane.