Which of the following statements about biological membranes is FALSE?

A) They are composed of a mixture of lipids and proteins in which lateral diffusion of components is possible.
B) Lipids and proteins move laterally at approximately the same rate within the membrane.
C) The faces of biological membranes are distinct and usually different in both composition and structure.
D) Phospholipids often require a specialized enzyme to facilitate movement across (flipping) the membrane.
E) They are often organized into smaller regions of specific function.